5-HIAA (5-hydroxyindoleacetic acid)
A major metabolite of seratonin, a biogenic amine found in the brain and other organs.  Functional deficits of seratonin in the central nervous system have been implicated in certain types of major mood disorders, and particularly in suicide and impulsivity.

abreaction
Emotional release or discharge after recalling a painful experience that has been repressed because it was not consciously tolerable.  A therapeutic effect sometimes occurs through partial or repeated discharge of the painful affect.

abstract attitude (categorical attitude)
A type of cognitive functioning that includes assuming a mental set voluntarily; shifting voluntarily from a specific aspect of a situation to the general; keeping in mind simultaneously various aspects of a situation; grasping the essentials of a whole, and breaking it into its parts and isolating them voluntarily; planning ahead ideationally; and/or thinking or performing symbolically.  A characteristic of many psychiatric disorders is the person's inability to assume the abstract attitude or to shift readily from the concrete to the abstract and back again as demanded by circumstances.

abulia
Lack of will or motivation, often expressed as inability to make decisions or set goals.

acculturation difficulty
A problem in adapting to or finding an appropriate way to adapt to a different culture or environment.  The problem is not based on any coexisting mental disorder.

acetylcholine
A neurotransmitter in the brain, where it helps to regulate memory, and in the peripheral nervous system, where it controls the actions of skeletal and smooth muscle.

acting out
Expressions of unconscious emotional conflicts or feelings in actions rather than words.  The person is not consciously aware of the meaning of such acts.  Acting out may be harmful or, in controlled situations, therapeutic (e.g., children's play therapy).

adrenergic
Referring to neural activation by catecholamines such as epinephrine, norepinephrine, and dopamine.

adrenergic system
That system of organs and nerves in which catecholamines are the neurotransmitters.

affect
Behavior that expresses a subjectively experienced feeling state (emotion; affect is responsive to changing emotional states, whereas mood refers to a pervasive and sustained emotion. Common affects are euphoria, anger, and sadness.

age-associated memory impairment (AAMI)
The mild disturbance in memory function that occurs normally with aging; benign senescent forgetfulness.

agitation (psychomotor agitation)
Excessive motor activity associated with a feeling of inner tension.  The activity is usually nonproductive and repetitious and consists of such behavior as pacing, fidgeting, wringing of the hands, pulling of clothes, and inability to sit still.

agnosia
Failure to recognize or identify objects despite intact sensory function; may be seen in dementia

agonist
In pharmacology, a substance that stimulates or mimics a receptor-mediated biological response by occupying cell receptors.

agoraphobia
Anxiety about being in places or situations in which escape might be difficult or embarrassing or in which help may not be available should a panic attack occur.  The fears typically relate to venturing into the open, of leaving the familiar setting of one's home, or of being in a crowd, standing in line, or traveling in a car or train.  Although agoraphobia usually occurs as a part of panic disorder, agoraphobia without a history of panic disorder has been described.

akathisia, neuroleptic-induced, acute
Complaints of restlessness accompanied by movements such as fidgeting of the legs, rocking from foot to foot, pacing, or inability to sit or stand.  Symptoms develop within a few weeks of starting or raising the dose of a neuroleptic medication or of reducing the dose of medication used to treat extrapyramidal symptoms.

akinesia
State of motor inhibition; reduced voluntary movement.

alexia
Loss of the ability to grasp the meaning of written or printed words and sentences.

alexithymia
A disturbance in affective and cognitive function that overlaps diagnostic entities but is common in psychosomatic disorders, addictive disorders, and posttraumatic stress disorder.  The chief manifestations are difficulty in describing or recognizing one's own emotions, a limited fantasy life, and general constriction in the affective life.

algophobia
Fear of pain.

alienation
The estrangement felt in a setting one views as foreign, unpredictable, or unacceptable.  For example, in depersonalization phenomena, feelings of unreality or strangeness produced a sense of alienation from one's self or environment.  In obsessions, which involve a fear of one's emotions, avoidance of situations that arouse emotions, and continuing effort to keep feelings out of awareness, there is alienation of affect.

alloplastic
Referring to adaptation by means of altering the external environment.  Contrast to autoplastic, which refers to the alteration of one's own behavior and responses.

alogia
Literally, speechlessness. Most commonly used to refer to the lack of spontaneity in speech and diminished flow of conversation that occur as negative symptoms in schizophrenia.

ambivalence
The coexistence of contradictory emotions, attitudes, ideas, or desires with respect to a particular person, object, or situation.  Ordinarily, the ambivalence is not fully conscious and suggests psychopathology only when present in an extreme form.

amentia
Subnormal development of the mind, with particular reference to intellectual capacities; a type of severe mental retardation.

amimia
A disorder of language characterized by an inability to make gestures or to understand the significance of gestures.

amines
Organic compounds containing the amino group (-NH2); of special importance in biochemistry and neurochemistry because of their role as neurotransmitters.  Epinephrine and norepinephrine are amines.

amnesia
Pathologic loss of memory; a phenomenon in which an area of experience becomes inaccessible to conscious recall.  The loss in memory may be organic, emotional, dissociative, or of mixed origin, and may be permanent or limited to a sharply circumscribed period of time.

amok
Acute indiscriminate homicidal mania.

amygdala
In the structure of the brain, part of the basal ganglia located on the roof of the temporal horn of the lateral ventricle at the inferior end of the caudate nucleus.  It is a structure in the forebrain that is an important component of the limbic system.

amyloid
Any one of various complex proteins that are deposited in tissues in different disease processes.  These proteins have an affinity for Congo red dye.  In neuropsychiatry, of particular interest are the beta-amyloid (A4) protein, which is the major component of the characteristic senile plaques of Alzheimer's disease, and the amyloid precursor protein (APP).

anaclitic
Literally, leaning on.  In psychoanalytic terminology, dependence of the infant on the mother substitute for a sense of well-being.  Normal behavior in childhood, but pathologic in later years.

analysis of variance (ANOVA)
A widely used statistical procedure for determining the significance of differences obtained on an experimental variable studied under two or more conditions.  Differences are commonly assigned to three aspects:  the individual differences among the subjects or patients studied; group differences, however classified (e.g., by sex); and differences according to the various treatments to which the subjects have been assigned.  The method can assess both the main effects of a variable and its interaction with other variables that have been studied simultaneously.

anamnesis
The developmental history of a patient and of his or her illness, especially recollections.

anankastic personality
Synonym for obsessive-compulsive personality.

androgyny
A combination of male and female characteristics in one person.

anhedonia
Inability to derive pleasure from previously pleasurable activities including eating, sex, hobbies, sports, social events, and family functions.

anima
In Jungian psychology, a person's inner being as opposed to the character or persona presented to the world.  Further, the anima may be the more feminine \"soul\" or inner self of a man, and the animus the more masculine soul of a woman.

anomie
Apathy, alienation, and personal distress resulting from the loss of goals previously valued.  Emile Durkheim popularized this term when he listed it as a principal reason for suicide.

ANOVA (analysis of variance)
A widely used statistical procedure for determining the significance of differences obtained on an experimental variable studied under two or more conditions.  Differences are commonly assigned to three aspects:  the individual differences among the subjects or patients studied; group differences, however classified (e.g., by sex); and differences according to the various treatments to which the subjects have been assigned.  The method can assess both the main effects of a variable and its interaction with other variables that have been studied simultaneously.

antagonist medication
A chemical entity extrinsic to endogenously produced substances that occupies a receptor, produces no physiologic effect, and prevents endogenous and exogenous chemicals from producing an effect on that receptor.

anterograde amnesia
Inability to form new memories of events that occur after the onset of the etiological condition of agent.

apathy
Lack of feeling, emotion, interest, or concern.

aphasia
Loss of the ability to use or understand words; may be seen in dementia.

aphonia
Inability to produce normal speech sounds; may be due to either organic or psychological causes.

apperception
Perception as modified and enhanced by one's own emotions, memories, and biases.

apraxia
Inability to carry out motor activities despite intact comprehension and motor function; may be seen in dementia.

assimilation
A Piagetian term describing a person's ability to comprehend and integrate new experiences.

ataxia
Loss of muscle coordination; irregularity of muscle action.

attributable risk
The rate of the disorder in exposed subjects that can be attributed to the exposure; derived from subtracting the rate (usually incidence or mortality) of the disorder of the nonexposed population from the corresponding rate of the exposed population.

auditory hallucination
A hallucination involving the perception of sound, most commonly of voices.  Some clinicians and investigators would not include those experiences perceived as coming from inside the head and would instead limit the concept of true auditory hallucinations to those sounds whose source is perceived as being external.  However, as used in DSM-IV, no distinction is made as to whether the source of the voices is perceived as being inside or outside of the head.

aura
A premonitory, subjective brief sensation (e.g. a flash of light) that warns of an impending headache or convulsion.  The nature of the sensation depends on the brain area in which the attack begins.  Seen in migraine and epilepsy.

autoeroticism
Sensual self-gratification.  Characteristic of, but not limited to, an early stage of emotional development.  Includes satisfactions derived from genital play, masturbation, fantasy, and oral, anal, and visual sources.

automatism
Automatic and apparently undirected nonpurposeful behavior that is not consciously controlled.  Seen in psychomotor epilepsy.

autoplastic
Referring to adaptation by changing the self.

avolition
Lack of initiative or goals; one of the negative symptoms of schizophrenia. The person may wish to do something, but the desire is without power or energy.

basal ganglia
Clusters of neurons located deep in the brain; they include the caudate nucleus and the putamen (corpus striatum), the globus pallidus, the subthalamic nucleus, and the substantia nigra. The basal ganglia appear to be involved in higher-order aspects of motor control, such as planning and execution of complex motor activity and the speed of movements.  Lesions of the basal ganglia produce various types of involuntary movements such as athetosis, chorea, dystonia, and tremor. The basal ganglia are involved also in the pathophysiology of Parkinson's disease, Huntington's disease, and tardive dyskinesia.  The internal capsule, containing all the fibers that ascend to or descend from the cortex, runs through the basal ganglia and separates them from the thalamus.

bestiality
Zoophilia; sexual relations between a human being and an animal.

beta-blocker
An agent that inhibits the action of beta-adrenergic receptors, which modulate cardiac functions, respiratory functions, and the dilation of blood vessels.  Beta-blockers are of value in the treatment of hypertension, cardiac arrhythmias, and migraine.  In psychiatry, they have been used in the treatment of aggression and violence, anxiety-related tremors and lithium-induced tremors, neuroleptic-induced akathisia, social phobias, panic states, and alcohol withdrawal.

bizarre delusion
A delusion that involves a phenomenon that the person's culture would regard as totally implausible.

blind spot
Visual scotoma, a circumscribed area of blindness or impaired vision in the visual field; by extension, an area of the personality of which the subject is unaware, typically because recognition of this area would cause painful emotions.

blocking
A sudden obstruction or interruption in spontaneous flow of thinking or speaking, perceived as an absence or deprivation of thought.

blunted affect
Significant reduction in the intensity of emotional expression.

body image
One's sense of the self and one's body.

bradykinesia
Neurologic condition characterized by a generalized slowness of motor activity.

bruxism
Grinding of the teeth, occurs unconsciously while awake or during stage 2 sleep.  May be secondary to anxiety, tension, or dental problems.

Capgras’ syndrome
The delusion that others, or the self, have been replaced by imposters.  It typically follows the development of negative feelings toward the other person that the subject cannot accept and attributers, instead, to the imposter.  The syndrome has been reported in paranoid schizophrenia ad, even more frequently, in organic brain disease.

catalepsy
A generalized condition of diminished responsiveness shown by trancelike states, posturing, or maintenance of physical attitudes for a prolonged period of time. May occur in organic or psychological disorders, or under hypnosis.

cataplexy
Sudden loss of postural tone without loss of consciousness, typically triggered by some emotional stimulus such as laughter, anger, or excitement. It is a characteristic of narcolepsy.

catatonic behavior
Marked motor abnormalities including motoric immobility (i.e., catalepsy or stupor), certain types of excessive motor activity (apparently purposeless agitation not influenced by external stimuli), extreme negativism (apparent motiveless resistance to instructions or attempts to be moved) or mutism, posturing or stereotyped movements, and echolalia or echopraxia.

catharsis
The healthful (therapeutic) release of ideas through \"talking out\" conscious material accompanied by an appropriate emotional reaction.  Also, the release into awareness of repressed (\"forgotten\") material from the unconscious.

cathexis
Attachment, conscious or unconscious, of emotional feeling and significance to an idea, an object, or, most commonly, a person.

causalgia
A sensation of intense pain of either organic or psychological origin.

cerea flexibilitas
The \"waxy flexibility\" often present in catatonic schizophrenia in which the patient's arm or leg remains in the position in which it is placed.

circumstantiality
Pattern of speech that is indirect and delayed in reaching its goal because of excessive or irrelevant detail or parenthetical remarks.  The speaker does not lose the point, as is characteristic of loosening of associations, and clauses remain logically connected, but to the listener it seems that the end will never be reached.

clanging
A type of thinking in which the sound of a word, rather than its meaning, gives the direction to subsequent associations.  Punning and rhyming may substitute for logic, and language may become increasingly a senseless compulsion to associate and decreasingly a vehicle for communication.  For example, in response to the statement \"That will probably remain a mystery,\" a patient said, \"History is one of my strong points.\"

climacteric
Menopausal period in women.  Sometimes use to refer to the corresponding age period in men.  Also called involutional period.

comorbidity
The simultaneous appearance of two or more illnesses, such as the co-occurrence of schizophrenia and substance abuse or of alcohol dependence and depression.  The association may reflect a causal relationship between one disorder and another or an underlying vulnerability to both disorders.

compensation
A defense mechanism, operating unconsciously, by which one attempts to make up for real or fancied deficiencies.  Also a conscious process in which one strives to make up for real or imagined defects of physique, performance skills, or psychological attributes.  The two types frequently merge.

competency
Generally refers to some minimal mental, cognitive, or behavioral ability, trait, or capability required to perform a particular legal act or to assume some legal role.

compulsion
Repetitive ritualistic behavior such as hand washing or ordering or a mental act such as praying or repeating words silently that aims to prevent or reduce distress or prevent some dreaded event or situation.  The person feels driven to perform such actions in response to an obsession or according to rules that must be applied rigidly, even though the behaviors are recognized to be excessive or unreasonable.

conative
Pertains to one's basic strivings as expressed in behavior and actions; volitional as contrasted with cognitive.

concordance
In genetic studies, the similarity in a twin pair with respect to the presence or absence of a disease or trait.

concrete thinking
Thinking characterized by immediate experience, rather than abstractions.  It may occur as a primary, developmental defect, or it may develop secondary to organic brain disease or schizophrenia.

condensation
A psychological process, often present in dreams, in which two or more concepts are fused so that a single symbol represents the multiple components.

confrontation
A communication that deliberately pressures or invites another to self-examine some aspect of behavior in which there is a discrepancy between self-reported and observed behavior.

conservatorship
The appointment of a person to manage and make decisions on behalf of an incompetent person regarding the latter's estate (e.g., authority to make contracts or sell property).

contingency reinforcement
In operant or instrumental conditioning, ensuring that desired behavior is followed by positive consequences and that undesired behavior is not rewarded.

control
The term is used in three contexts:  1) keeping the relevant conditions of an experiment constant,  2) causing an independent variable to vary in a specified and known manner, and  3) using a spontaneously occurring and discoverable fact as a check or standard of comparison to evaluate the facts obtained after the manipulation of the independent variable.

control group
In the ideal case, a group of subjects matched as closely as possible to an experimental group of subjects on all relevant aspects and exposed to the same treatments except the independent variable under investigation.

conversation symptom
A loss, of, or alternation in, voluntary motor or sensory functioning suggesting a neurological or general medical condition.  Psychological factors are judged to be associated with the development of the symptom, and the symptom is not fully explained by a neurological or general medical condition or the direct effect of a substance.  The symptom is not intentionally produced or feigned and is not culturally sanctioned.

coprophagi
Eating of filth or feces.

correlation
The extent to which two measures vary together, or a measure of the strength of the relationship between two variables.  It is usually expressed by a coefficient that varies between +1.0 (perfect agreement) and -1.0 (a perfect inverse relationship).  A correlation coefficient of 0.0 would mean a perfectly random relationship.  The correlation coefficient signifies the degree to which knowledge of one score or variable can predict the score on the other variable.  A high correlation between two variables does not necessarily indicate a causal relationship between them; the correlation may follow because each of the variables is highly related to a third, as yet unmeasured, factor.

counterphobia
Deliberately seeking out and exposing oneself to, rather than avoiding, the object or situation that is consciously or unconsciously feared.

countertransference
The therapist's emotional reactions to the patient that are based on the therapist's unconscious needs and conflicts, as distinguished from his or her conscious responses to the patient's behavior.  Countertransference may interfere with the therapist's ability to understand the patient and may adversely affect the therapeutic technique.  Currently, there is emphasis on the positive aspects of Countertransference and its use as a guide to a more empathic understanding of the patient.

cretinism
A type of mental retardation and bodily malformation caused by severe, uncorrected thyroid deficiency in infancy and early childhood.

cri du chat
A type of mental retardation.  The name is derived from a catlike cry emitted by children with this disorder, which is caused by partial deletion of chromosome 5.

criterion variable
Something to be predicted.

cyclothymia
Affective disorder involving periods of depression and hypomania, but with briefer mood swings and less severe symptoms than Bipolar Disorder.

Da Costa’s syndrome
Neurocirculatory asthenia; \"soldier's heart\"; a functional disorder of the circulatory system that is usually a part of an anxiety state or secondary to hyperventilation.

decompensation
The deterioration of existing defenses, leading to an exacerbation of pathological behavior.

defense mechanism
Automatic psychological process that protects the individual against anxiety and from awareness of internal or external stressors or dangers.  Defense mechanisms mediate the individual's reaction to emotional conflicts and to external stressors.  Some defense mechanism (e.g., projection, splitting, and acting out) are almost invariably maladaptive.  Others, such as suppression and denial, may be either maladaptive or adaptive, depending on their severity, their inflexibility, and the context in which they occur.

déjà vu
A paramnesia consisting of the sensation or illusion that one is seeintg what one has seen before.

delusion
A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary.  The belief is not one ordinarily accepted by other members of the person's culture or subculture (e.g., it is not an article of religious faith).  When a false belief involved a value judgement, it is regarded as a delusion only when the judgement is so extreme as to defy credibility.  Delusional conviction occurs on a continuum and can sometimes be inferred from an individual's behavior.  It is often difficult to distinguish between a delusion and an overvalued idea (in which case the individual has an unreasonable belief or idea but does not hold it as firmly as is the case with a delusion).

delusion of control
The belief that one's feelings, impulses, thoughts, or actions are not one's own but have been imposed by some external force.

delusion of reference
A delusion whose theme is that events, objects, or other persons in one's immediate environment have a particular and unusual significance.  These delusions are usually of a negative or pejorative nature, but also may be grandiose in content.  This differs from an idea of reference, in which the false belief is not as firmly held nor as fully organized into a true belief.

delusional jealousy
The delusion that one's sexual partner is unfaithful.

demand characteristics
The sum total of cues that communicates the purpose of the experiment and the nature of the behavior expected of the subject.  (The cues are derived from the manner in which the subject is solicited, the manner in which he or she is treated by the experimenter, the scuttlebutt about the experiment, the experimental instructions, and, most important, the experimental procedure itself.)  Subjects may confirm the investigator's hypothesis in an effort to behave appropriately rather than respond directly to the independent variables under investigation.  By extension, as applied to nonexperimental settings, the tendency of individuals live up to what is implicitly expected of them, a factor that may play a major role in the outcome of treatment.

dependent variable
That aspect of the subject that is measured after the manipulation of the independent variable and that is assumed to vary as a function of the independent variable.

depersonalization
Feelings of unreality or strangeness concerning either the environment, the self, or both. This is characteristic of depersonalization disorder and may also occur in schizotypal personality disorder, schizophrenia, and in those persons experiencing overwhelming anxiety, stress, or fatigue.

derailment
(\"loosening of associations\")  A pattern of speech in which a person's ideas slip off one track onto another that is completely unrelated or only obliquely related.  In moving from one sentence or clause to another, the person shifts the topic idiosyncratically from one frame of reference to another and things may be said in juxtaposition that lack a meaningful relationship.  This disturbance occurs between clauses, in contrast to incoherence, in which the disturbance is within clauses.  An occasional change of topic without warning or obvious connection does not constitute derailment.

derealization
An alteration in the perception or experience of the external world so that it seems strange or unreal (e.g., people may seem unfamiliar or mechanical).

dereistic
Mental activity that is not in accordance with reality, logic, or experience.

detachment
A behavior pattern characterized by general aloofness in interpersonal contact; may include intellectualization, denial, and superficiality.

diminished capacity
Refers to \"insufficient cognitive ability to achieve the state of mind requisite for the commission of a crime.\"  Sometimes referred to as \"partial insanity\", this doctrine permits a court to consider the impaired mental state of the defendant for purposes of reducing punishment or lowering the degree of the offense being charged.

diplopia
Double vision due to paralysis of the ocular muscles; seen in inhalant intoxication and other conditions affecting the oculomotor nerve.

disconnection syndrome
Term coined by Norman Geschwind (1926-1984) to describe the interruption of information transferred from one brain region to another.

discordance
In genetic studies, dissimilarity in a twin pair with respect to the presence of absence of a disease or trait.

disinhibition
Freedom to act according to one's inner drives or feelings, with less regard for restraints imposed by cultural norms or one's superego; removal of an inhibitory, constraining, or limiting influence, as in the escape from higher cortical control in neurologic injury, or in uncontrolled firing of impulses, as when a drug interferes with the usual limiting or inhibiting action of GABA within the central nervous system.

disorientation
Confusion about the time of day, date, or season (time), where one is (place), or who one is (person).

displacement
A defense mechanism, operating unconsciously, in which emotions, ideas, or wishes are transferred from their original object to a more acceptable substitute; often used to allay anxiety.

dissociation
A disruption in the usually integrated functions of consciousness, memory, identity, or perception of the environment.  The disturbance may be sudden or gradual, transient or chronic.

distractibility
The inability to maintain attention, that is the shifting from one area or topic to another with minimal provocation, or attention being drawn too frequently to unimportant or irrelevant external stimuli.

double-blind
Referring to a study design in which a number of treatments, usually one or more drugs and a placebo, are compared in such a way that neither the patient nor the persons directly involved in the treatment know which preparation is being administered.

drive
Basic urge, instinct, motivation; a term used to avoid confusion with the more purely biological concept of instinct.

dyad
A two-person relationship, such as the therapeutic relationship between doctor and patient in individual psychotherapy.

dysarthria
Difficulty in speech production due to lack of coordination of the speech apparatus.

dyskinesia
Any disturbance of movement. It may also be induced by medication.

dyslexia
Inability or difficulty in reading, including word-blindness and a tendency to reverse letters and words in reading and writing.

dysphoric mood
An unpleasant mood, such as sadness, anxiety, or irritability.

dyssomnia
Primary disorders of sleep or wakefulness characterized by insomnia or hypersomnia as the major presenting symptom.  Dyssomnias, are disorders of the amount, quality, or timing of sleep.

dystonia
Disordered tonicity of muscles.

echolalia
Parrot-like repetition of overheard words or fragments of speech. It may be part of a developmental disorder, a neurologic disorder, or schizophrenia. Echolalia tends to be repetitive and persistent and is often uttered with a mocking, mumbling, or staccato intonation.

echopraxia
Imitative repetition of the movements, gestures, or posture of another. It may be part of a neurologic disorder or of schizophrenia.

ecological validity
The extent to which controlled experimental results can be generalized beyond the confines of the particular experimental context of a variety of contexts in the real world.

ego
In psychoanalytic theory, one of the three major divisions in the model of the psychic apparatus, the others being the id and the superego.  The ego represents the sum of certain mental mechanisms, such as perception and memory, and specific defense mechanisms.  It serves to mediate between the demands of primitive instinctual drives (the id), of internalized parental and social prohibitions (the superego), and of reality.  The compromises between these forces achieved by the ego tend to resolve intrapsychic conflict and serve an adaptive and executive function.  Psychiatric usage of the term should not be confused with common usage, which connotes self-love or selfishness.

ego-dystonic
Referring to aspects of a person's behavior, thoughts, and attitudes that are viewed by the self as repugnant or inconsistent with the total personality.

ego ideal
The part of the personality that comprises the aims and goals for the self; usually refers to the conscious or unconscious emulation of significant figures with whom one has identified.  The ego ideal emphasizes what one should be or do in contrast to what one should not be or not do.

eidetic image
Unusually vivid and apparently exact mental image; may be a memory, fantasy, or dream.

elaboration
An unconscious process consisting of expansion and embellishment of detail, especially with reference to a symbol or representation in a dream.

elevated mood
An exaggerated feeling of well-being, or euphoria or elation.  A person with elevated mood may describe feeling \"high\", \"ecstatic\", \"on top of the world\", or \"up in the clouds\".

engram
A memory trace; a neurophysiological process that accounts for persistence of memory.

ethnology
A science that concerns itself with the division of human beings winto races and their origin, distribution relations, and characteristics.

euthymic mood
Mood in the \"normal\" range, with implies the absence of depressed or elevated mood.

expansive mood
Lack of restraint in expressing one's feelings, frequently with an overvaluation of one's significance or importance.

experimental design
The logical framework of an experiment that maximizes the probability of obtaining or detecting real effects and minimizes the likelihood of ambiguities regarding the significance of the experimentally observed differences.

experimenter bias
Experimenter expectations that are inadvertently communicated to patients or subjects.  Such expectations may influence experimental findings.

external validity
The applicability of the generalizations that may be made from the experimental findings beyond the occasion with those specific subjects, experimental conditions, experimenters, or measurements.

extinction
The weakening of a reinforced operant response as a result of ceasing reinforcement.

extraversion
A state in which attention and energies are largely directed outward from the self as opposed to inward toward the self, as in introversion.

fantasy
An imagined sequence of events or mental images (e.g. daydreams) that serves to express unconscious conflicts, to gratify unconscious wishes, or to prepare for anticipated future events.

flashback
A recurrent of a memory, feeling, or perceptual experience from the past .

flat affect
Absence or near absence of any signs of affective expression.

flight of ideas
A nearly continuous flow of accelerated speech with abrupt changes from topic to topic that are usually based on understandable associations, distracting stimuli, or plays on words.  When severe, speech may be disorganized and incoherent. Flight of ideas is characteristic of manic episodes, but it may occur also in organic mental disorders, schizophrenia, other psychoses, and, rarely, acute reactions to stress.

flooding (implosion)
A behavior therapy procedure for phobias and other problems involving maladaptive anxiety, in which anxiety producers are presented  in intense forms, whether in imagination or in real life.  The presentations, which act as desensitizers, are continued until the stimuli no longer produce disabling anxiety.

formal thought disorder
An inexact term referring to a disturbance in the form of thinking rather than to abnormality of content

formication
The tactile hallucination or illusion that insects are crawling on the body or under the skin.

fragmentation
Separation into different parts, or preventing their integration, or detaching one or more parts from the rest.  A fear of fragmentation of the personality, also known as disintegration anxiety, is often observed in patients whenever they are exposed to repetitions of earlier experiences that interfered with development of the self.  This fear may be expressed as feelings of falling apart, as a loss of identity, or as a fear of impending loss of one's vitality and of psychological depletion.

free association
In psychoanalytic therapy, spontaneous, uncensored verbalization by the patient or whatever comes to mind.

frotteurism
One of the paraphilias, consisting of recurrent, intense sexual urges involving touching and rubbing against a nonconsenting person; common sites in which such activities take place are crowded trains, buses, and elevators.  Fondling the victim may be part of the condition and is called toucherism.

fusion
The union and integration of the instincts and drives so that they complement each other and help the organism to deal effectively with both internal needs and external demands.  Aggression can be used in the effective pursuit of the love object, for instance, and need not destroy object or self.

gender dysphoria
A persistent aversion toward some or all of those physical characteristics or social roles that connote one's own biological sex.

gender identity
A person's inner conviction of being male or female.

gender role
Attitudes, patterns of behavior, and personality attributes defined by the culture in which the person lives as stereotypically \"masculine\" or feminine\" social roles.

globus hystericus
The disturbing sensation of a lump in the throat.

glossolalia
Gibberish-like speech or \"speaking in tongues\".

grandiosity
An inflated appraisal of one's worth, power, knowledge, importance, or identity.  When extreme, grandiosity may be of delusional proportions.

gustatory hallucination
A hallucination involving the perception of taste (usually unpleasant).

hallucination
A sensory perception that has the compelling sense of reality of a true perception but that occurs without external stimulation of the relevant sensory organ.  Hallucinations should be distinguished from illusions, in which an actual external stimulus is misperceived or misinterpreted.  The person may or may not have insight into the fact that he or she is having a hallucination.  One person with auditory hallucinations may recognize that he or she is having a false sensory experience, whereas another may be convinced that the source of the sensory experience has an independent physical reality.  The term hallucination is not ordinarily applied to the false perceptions that occur during dreaming, while falling asleep (hypnogogic), or when awakening (hypnopompic).  Transient hallucinatory experiences may occur in people without a mental disorder.

hedonism
Pleasure-seeking behavior.  Contrast with anhedonia.

heuristic
Serving to encourage discovery of problem solutions.

hippocampus
Olfactory brain; a sea-horse-shaped structure located within the brain that is an important part of the limbic system.  The hippocampus is involved in some aspects of memory, in the control of the autonomic functions, and in emotional expression.

holding environment
A responsive, nurturing milieu for the developing child, including physical holding as well as the mother's or primary caregiver's preoccupation with the child and her ability to soothe, comfort, and reduce the tension in her infant. Ideally, the mother reflects back the child's worth and value and in other ways responds appropriately to his or her needs. Lack of such responsivity is often termed empathic failure.  In the psychotherapeutic relationship, holding environment refers to a therapeutic ambiance or setting that permits the patient to experience safety, thereby facilitating psychotherapeutic work.

hyperacusis
Inordinate sensitivity to sounds; it may be on an emotional or an organic basis.

hypersomnia
Excessive sleepiness, as evidenced by prolonged nocturnal sleep, difficulty maintaining an alert awake state during the day, or undesired daytime sleep episodes.

hypnogogic
Referring to the semiconscious state immediately preceding sleep; may include hallucinations that are of no pathological significance.

hypnopompic
Referring to the state immediately preceding awakening; may include hallucinations that are of no pathological significance.

hypomania
Mild mania without much change in behavior, but accompanied by sound associations and distractibility.

id
In Freudian theory, the part of the personality that is the unconscious source of unstructured desires and drives.

idealization
A mental mechanism in which the person attributes exaggeratedly positive qualities to the self or others.

ideas of reference
The feeling that casual incidents and external events have a particular and unusual meaning that is specific to the person.  This is to be distinguished from a delusion or reference, in which there is a belief that is held with delusional conviction.

identification
A defense mechanism, operating unconsciously, by which one patterns oneself after some other person.  Identification plays a major role in the development of one's personality and specifically of the superego.  To be differentiated from imitation or role modeling, which is a conscious process.

idiot savant
A person with gross mental retardation who nonetheless is capable of performing certain remarkable feats in sharply circumscribed intellectual areas, such as calendar calculation or puzzle solving.

illusion
A misperception of misinterpretation of a real external stimulus, such as hearing the rustling of leaves as the sound of voices.

imprinting
A term in ethology referring to a process similar to rapid learning or behavioral patterning that occurs at critical points in very early stages of animal development.  The extent to which imprinting occurs in human development has not been established.

inappropriate affect
Discordance between affective expression and the content of speech or ideation.

incidence
The number of cases of disease that come into being during a specific period of time.

incoherence
Speech or thinking that is essentially incomprehensible to others because words or phrases are joined together without a logical or meaningful connection.  This disturbance occurs within clauses, in contrast to derailment, in which the disturbance is between clauses.  This has sometimes been referred to as \"word salad\" to convey the degree of linguistic disorganization.  Mildly ungrammatical constructions or idiomatic usages characteristic of particular regional or cultural backgrounds, lack of education, or low intelligence should not be considered incoherence.  The term is generally not applied when there is evidence that the disturbance in speech is due to an aphasia.

independent variable
The variable under the experimenter's control.

individuation
A process of differentiation, the end result of which is development of the individual personality that is separate and distinct from all others.

indoleamine
One of a group of biogenic amines (e.g. seratonin) that contains a five-membered, nitrogen-containing indole ring and an amine group within its chemical structure.

informed consent
In medical jurisprudence, a physician must disclose to a patient sufficient information regarding a proposed procedure to enable the patient to make a knowing decision about whether to participate.  In addition to sufficient information, any consent given must be voluntary and made by a person considered legally competent.

inhibition
Behavioral evidence of an unconscious defense against forbidden instinctual drives; may interfere with or restrict specific activities.

initial insomnia
Difficulty in falling asleep.

insanity
In law, the term denotes that degree of mental illness that negates an individual's legal responsibility ort capacity.

insomnia
A subjective complaint of difficulty falling or staying asleep or poor sleep quality.

instinct
An inborn drive.  The primary human instincts include self-preservation, sexuality, and, according to some proponents, the death instinct, of which aggression is one manifestation.

integration
the useful organization and incorporation of both new and old data, experience, and emotional capacities into the personality.  Also refers to the organization and amalgamation of functions at various levels of psychosexual development.

intellectualization
A mental mechanism in which the person engages in excessive abstract thinking to avoid confrontation with conflicts or disturbing feelings.

intersex condition
A condition in which an individual shows intermingling, in various degrees, of the characteristics of each sex, including physical form, reproductive organs, and sexual behavior.

intervening variable
Something intervening between an antecedent circumstance and its consequence, modifying the relation between the two.  For example, appetite can be an intervening variable determining whether or not a given food will be eaten.  The intervening variable may be inferred rather than empirically detected.

introspection
Self-observation; examination of one's feelings, often as a result of psychotherapy.

introversion
Preoccupation with oneself and accompanying reduction of interest in the outside world.  Contrast to extraversion.

irritable mood
Easily annoyed and provoked to anger.

isolation
A defense mechanism operating unconsciously central to obsessive-compulsive phenomena in which the affect is detached from an idea and rendered unconscious, leaving the conscious idea colorless and emotionally neutral.

Klinefelter’s syndrome
Chromosomal defect in males in which there is an extra X chromosome; manifestations may include underdeveloped testes, physical feminization, sterility, and mental retardation.

la bele indifference
Literally, \"beautiful indifference\".  Seen in certain patients with conversion disorders who show an inappropriate lack of concern about their disabilities.

labile affect
Abnormal variability in affect with repeated, rapid, and abrupt shifts in affective expression.

latent content
The hidden (i.e. unconscious) meaning of thoughts or actions, especially in dreams or fantasies. In dreams, it is expressed in distorted, disguised, condensed, and symbolic form.

learned helplessness
A condition in which a person attempts to establish and maintain contact with another by adopting a helpless, powerless stance.

lethologica
Temporary inability to remember a proper noun or name.

libido
The psychic drive or energy usually associated with the sexual instinct.  (Sexual is used here in the broad sense to include pleasure and love-object seeking.)

living will
Procedure by which competent persons can, under certain situations, direct their doctors to treat them in a prescribed way if they become incompetent (e.g., withdraw life-saving medical care if in a vegetative state).

locus coeruleus
A small area in the brain stem containing norepinephrine neurons that is considered to be a key brain center for anxiety and fear.

long-term memory
The final phase of memory in which information storage may last from hours to a lifetime.

loosening of associations
A disturbance of thinking shown by speech in which ideas shift from one subject to another that is unrelated or minimally related to the first.  Statements that lack a meaningful relationship may be juxtaposed, or speech may shift suddenly from one frame of reference to another.  The speaker gives no indication of being aware of the disconnectedness, contradictions, or illogicality of speech.

M’Naughten rule
In 1843, the English House of Lords ruled that a person was not responsible for a crime if the accused \"was laboring under such a defect of reason from a disease of mind as not to know the nature and quality of the act; or, if he knew it, that he did not know he was going what was wrong\".  This rule, or some derivation of it, is still applied in many states today.

macropsia
The visual perception that objects are larger than they actually are.

magical thinking
thinking A conviction that thinking equates with doing. Occurs in dreams in children, in primitive peoples, and in patients under a variety of conditions. Characterized by lack of realistic relationship between cause and effect.

mania
A form of psychosis characterized by excessive excitement, exalted feelings, delusions of grandeur, elevation of mood, psychomotor over-activity and over-production of ideas.

manifest content
The remembered content of a dream or fantasy, as contrasted with latent content, which is concealed and distorted.

masochism
Pleasure derived from physical or psychological pain inflicted on oneself either by oneself or by others.  It is called sexual masochism and classified as a paraphilias when it is consciously sought as a part of the sexual act or as a prerequisite to sexual gratification.  It is the converse of sadism, although the two tend to coexist in the same person.

mean
The arithmetic average of a set of observations; the sum of scores divided by the number of scores.

median
The middle value in a set of values that have been arranged in order from highest to lowest.

memory consolidation
The physical and psychological changes that take place as the brain organizes and restructures information that may become a permanent part of memory.

MHPG (3-methoxy-4-hydroxyphenylglycol)
A major metabolite of brain norepinephrine excreted in urine.

micropsia
The visual perception that objects are smaller than they actually are.

middle insomnia
Awakening in the middle of the night followed by eventually falling back to sleep, but with difficulty.

mirroring
1) The empathic responsiveness of the parent to the developing child's grandiose-exhibitionistic needs. Parental expressions of delight in the child's activities signal that the child's wishes and experiences are accepted as legitimate. This teaches the child which of his or her potential qualities are most highly esteemed and valued. Mirroring validates the child as to who he or she is and affirms his or her worth. The process transforms archaic aims to realizable aims, and it determines in part the content of the self-assessing, self-monitoring functions and their relationships to the rest of the personality. The content of the superego is the residue of the mirroring experience.  2) A technique in psychodrama in which another person in the group plays the role of the patient, who watches the enactment as if gazing into a mirror. The first person may exaggerate one or more aspects of the patient's behavior. Following the portrayal, the patient is usually encouraged to comment on what he or she has observed.

mode
The most frequently occurring observation in a set of observations.

mood
A pervasive and sustained  emotion that colors the perception of the world.  Common examples of mood include depression, elation, anger, and anxiety.  In contrast to affect, which refers to more fluctuating changes in emotional \"weather\", mood refers to a more pervasive and sustained emotional \"climate\".

mood-congruent psychotic features
Delusions or hallucinations whose content is entirely consistent with the typical themes of a depressed or manic mood.  If the mood is depressed, the content of the delusions or hallucinations would involve themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment.  The content of the delusion may include themes of persecution if these are based on self-derogatory concepts such as deserved punishment.  If the mood is manic, the content of the delusions or hallucinations would involve themes of inflated worth, power, knowledge, or identity, or a special relationship to a deity or a famous person.  The content of the delusion may include themes of persecution if these are based on concepts such as inflated worth or deserved punishment.

mood-incongruent psychotic features
Delusions or hallucinations whose content is not consistent with the typical themes of a depressed or manic mood.  In the case of depression, the delusions or hallucinations would not involve themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment.  In the case of mania, the delusions or hallucinations would not involve themes of inflated worth, power, knowledge, or identity, or a special relationship to a deity or a famous person.  Examples of mood-incongruent psychotic features include persecutory delusions (without self-derogatory or grandiose content), thought insertion, thought broadcasting, and delusions of being controlled whose content has no apparent relationship to any of the themes listed above.

negative symptoms
Most commonly refers to a group of symptoms characteristic of schizophrenia that include loss of fluency and spontaneity of verbal expression, impaired ability to focus or sustain attention on a particular task, difficulty in initiating or following through on tasks, impaired ability to experience pleasure to form emotional attachment to others, and blunted affect.

negativism
Opposition or resistance, either covert or overt, to outside suggestions or advice.  May be seen in schizophrenia.

neologism
In psychiatry, a new word or condensed combination of several words coined by a person to express a highly complex idea not readily understood by others; seen in schizophrenia and organic mental disorders.

neurotic disorder
A mental disorder in which the predominant disturbance is a distressing symptom or group of symptoms that one considers unacceptable and alien to one's personality.  There is no marked loss of reality testing; behavior does not actively violate gross social norms, although it may be quite disabling.  The disturbance is relatively enduring or recurrent without treatment and is not limited to a mild transitory reaction to stress.  There is no demonstrable organic etiology.

nihilistic delusion
The delusion of nonexistence of the self or part of the self, or of some object in external reality.

nonparametric tests of significance
Specialized statistical procedures that do not require assumptions of normality when data do not satisfy certain statistical assumptions, such as being normally distributed.  These procedures are often based on an analysis of ranks rather than on the distribution of the actual scores themselves.

null hypothesis
Predicting that an experiment will show no difference between conditions or no relationship between variables. Statistical tests are then applied to the results of the experiment to try to disprove the null hypothesis.  Testing requires a computation to determine the limits within which two groups may differ in their results (e.g., an experimental and a control group) even though if the experiment were often repeated or the groups were larger no difference would be found. The probability of the obtained difference being found if no true difference existed is commonly expressed as a P value (e.g., P less than .05 that the null hypothesis is true).

nystagmus
Involuntary rhythmic movements of the eyes that consist of small-amplitude rapid tremors in one direction and a larger, slower, recurrent sweep in the opposite direction.  Nystagmus may be horizontal, vertical, or rotary.

object relations
The emotional bonds between one person and another, as contrasted with interest in and love for the self; usually described in terms of capacity for loving and reacting appropriately to others.

obsession
Recurrent and persistent thought, impulse, or image experienced as intrusive and distressing.  Recognized as being excessive and unreasonable even though it is the product of one's mind.  This thought, impulse, or image cannot be expunged by logic or reasoning.

Oedipus complex
Attachment of the child to the parent of the opposite sex, accompanied by envious and aggressive feelings toward the parent of the same sex.  These feelings are largely repressed (i.e. made unconscious) because of the fear of displeasure or punishment by the parent of the same sex.  In its original use, the term applied only to the boy or man.

olfactory hallucination
A hallucination involving the perception of odor, such as of burning rubber or decaying fish.

ontogenetic
Pertaining to the development of the individual.

operant conditioning (instrumental conditioning)
A process by which the results of the person's behavior determine whether the behavior is more or less likely to occur in the future.

operational definition
The meaning of a concept when it is translated to terms amenable to systematic observation and measurement (e.g., temperature defined by a thermometer reading under standard conditions).

orientation
Awareness of one's self in relation to time, place, and person.

overcompensation
A conscious or unconscious process in which a real or imagined physical or psychological deficit generates exaggerated correction.

overdetermination
The concept of multiple unconscious causes of an emotional reaction or symptom.

overvalued idea
An unreasonable and sustained belief that is maintained with less than delusional intensity (i.e., the person is able to acknowledge the possibility that the belief may not be true).  The belief is not one that is ordinarily accepted by other members of the person's culture or subculture.

panic attacks
Discrete periods of sudden onset of intense apprehension, fearfulness, or terror, often associated with feelings of impending doom. During these attacks there are symptoms such as shortness of breath or smothering sensations; palpitations, pounding heart, or accelerated heart rate; chest pain or discomfort; choking; and fear of going crazy or losing control.  Panic attacks may be unexpected (uncued), in which the onset of the attack is not associated with a situational trigger and instead occurs \"out of the blue\"; situationally bound, in which the panic attack almost invariably occurs immediately on exposure to, or in anticipation of, a situational trigger (\"cue\"); and situationally predisposed, in which the panic attack is more likely to occur on exposure to a situational trigger but is not invariably associated with it.

panic attacks - situationally bound
The panic attack almost invariably occurs immediately on exposure to, or in anticipation of, a situational trigger (\"cue\").

panic attacks - situationally predisposed
The panic attack is more likely to occur on exposure to a situational trigger but is not invariably associated with it.

panic attacks - unexpected (uncued)
The onset of the panic attack is not associated with a situational trigger and instead occurs \"out of the blue\".

parameter
Any quantitative value that a variable can take.

parametric study
One that examines the effects on a dependent variable of variations, usually across a broad range, in the base values of the independent variable.

parametric tests of significance
Tests based on the assumption that the form of the distribution of the observations is known, usually a so-called normal distribution.  Widely used tests based on such an assumption include analysis of variance, t tests, and Pearson coefficient of correlation.

paranoia
A condition characterized by the gradual development of an intricate, complex, and elaborate system of thinking based on (and often proceeding logically from) misinterpretation of an actual event; a delusional disorder.  Despite its chronic course, this condition does not seem to interfere with thinking and personality.  To be distinguished from schizophrenia, paranoid type.

paranoid ideation
Ideation, of less than delusional proportions, involving suspiciousness or the belief that one is being harassed, persecuted, or unfairly treated.

paraphilias
One of the major groups of sexual disorders; in DSM-IV, this group includes exhibitionism, fetishism, frotteurism, pedophilia, sexual masochism, sexual sadism, voyeurism, transvestic fetishism, and paraphilias not otherwise specified, which includes necrophilia and klismaphilia.  The paraphilias (also called perversions or sexual deviations) are recurrent, intense sexual urges and sexually arousing fantasies that involve nonhuman objects, children or other nonconsenting persons, or the suffering or humiliation of oneself or the sexual partner.

parapraxis
A faulty act, blunder, or lapse of memory such as a slip of the tongue or misplacement of an article.  According to Freud, these acts are caused by unconscious motives.

parasomnia
Abnormal behavior or physiological events occurring during sleep or sleep-wake transitions.

paresis
Weakness of organic origin; incomplete paralysis; term often used instead of general paralysis.

paresthesias
Abnormal tactile sensation, often described as burning, pricking, tickling, tingling, or creeping.

pathognomonic
A symptom or group of symptoms that are specifically diagnostic or typical of a disease.

pedophilia
One of the paraphilias, characterized by marked distress over, or acting on, urges involving sexual activity with a prepubescent child who, more often than not, is of the same sex.

pellagra
A vitamin B3 (nicotinamide) deficiency that may be a cause of major mental symptoms such as delusions and impaired thinking, as well as physical symptoms such as dermatitis.

period prevalence
A measure that expresses the total number of cases of a disease known to have existed at some time during a specified period. It is the sum of point prevalence and incidence.

persecutory delusion
A delusion in which the central theme is that one (or someone to whom one is close) is being attacked, harassed, cheated, persecuted, or conspired against.

perseveration
Tendency to emit the same verbal or motor response again and again to varied stimuli.

personality
Enduring patterns of perceiving, relating to, and thinking about the environment and oneself.  Personality traits are prominent aspects of personality that are exhibited in a wide range of important social and personal contexts.  Only when personality traits are inflexible and maladaptive and cause either significant functional impairment or subjective distress do they constitute a Personality disorder.

phobia
A persistent, irrational fear of a specific object, activity, or situation (the phobic stimulus) that results in a compelling desire to avoid it.  This often leads either to avoidance of the phobic stimulus or to enduring it with dread.

phomological disorder
Articulation disorder; a communication disorder characterized by failure in developmentally expected speech that is appropriate for age or dialect.  Speech sounds may be omitted, substituted, or distorted, as in saying \"w\" for \"r\" or \"f\" for \"th\".

phrenology
Theory of the relationship between the structure of the skull and mental traits.

placebo
In psychopharmacology, a pill that contains no pharmacologically active ingredient.

placebo effect
Either therapeutic effects or side effects following the ingestion of a placebo.  By extension, one may speak of a placebo effect as comprising the nonspecific aspects of any treatment procedure, usually mediated by the patient's expectations of improvement, such as the placebo effect of psychotherapy.

plaques
Certain areas of the brain that have undergone a specific form of degeneration.  Senile plaques (neuritic plaques) consist of a central amyloid core surrounded by a less densely staining zone composed of abnormal neurons, with many axonal and dendritic processes and masses of paired helical filaments.  In Alzheimer's disease, they are particularly dense in the amygdaloid complex and the hippocampus.  The relationship between the abnormal protein fibers inside neurons (the paired helical filaments) and those outside the cells (i.e. amyloid) is currently unknown.  The AD-DP gene, which codes for the beta-amyloid protein that accumulates in the blood vessel walls and in the neuronal tissue in both Alzheimer's and aged Down brains, maps to chromosome 21.

pleasure principle
The psychoanalytic concept that people instinctually seek to avoid pain and discomfort and strive for gratification and pleasure.  In personality development theory, the pleasure principle antedates and subsequently comes in conflict with the reality principle.

point prevalence
The frequency of the disease at a designated point in time.

polyphagia
Pathological overeating.  Also known as bulimia.

population
A statistical concept that refers to all individuals or instances that theoretically could be available for study or measurement.  Statistical inference involves generalizing from the observation of some specified sample to the population.

postural hypotension
A sudden and abnormally large drop in blood pressure that occurs upon standing and may result in fainting.

poverty of speech
Restriction in the amount of speech; spontaneous speech and relies to questions range from brief and unelaborated to monosyllabic or no response at all.  When the amount of speech is adequate, there may be a poverty of content if the answer is vague or if there is a substitution of stereotyped or obscure phrases for meaningful responses.

practice effects
The modifications in task performances as a result of repeated trials or training in the task.

preconscious
Thoughts that are not in immediate awareness but that can be recalled by conscious effort.

predictor variable
The test or other form of performance that is used to predict the person's status on a criterion variable.  For example, scores on the Scholastic Aptitude Test might be used to predict the criterion \"finishing college within the top 33% of graduating class\".  Scores on the SAT would be predictor scores.

pregenital
In psychoanalysis, refers to the period of early childhood before the genitals have begun to exert the predominant influence in the organization or patterning of sexual behavior.  Oral and anal influences predominate during this period.

pressured speech
Speech that is increased in amount, accelerated, and difficult to impossible to interrupt.  Usually it is also loud and emphatic.  Frequently the person talks without any social stimulation and may continue to talk even though no one is listening.

prevalence
Frequency of a disorder, used particularly in epidemiology to denote the total number of cases existing within a unit of population at a given time or over a specified period.

primary gain
The relief from emotional conflict and the freedom from anxiety achieved by a defense mechanism.  Contrast with secondary gain.

primary process
In psychoanalytic theory, the generally unorganized mental activity characteristic of the unconscious.  This activity is marked by the free discharge of energy and excitation without regard to the demands of environment, reality, or logic.

prodrome
An early or premonitory sign or symptom of a disorder.

projection
A defense mechanism, operating unconsciously, in which what is emotionally unacceptable in the self is unconsciously rejected and attributed (projected) to others.

projective identification
Referring to the unconscious process of projection of one or more parts of the self or of the internal object into another person (such as the mother).  What is projected may be an intolerable, painful, or dangerous part of the self or object (the bad object). It may also be a valued aspect of the self or object (the good object) that is projected into the other person for safekeeping.  The other person is changed by the projection and is dealt with as though he or she is in fact characterized by the aspects of the self that have been projected.

projective tests
Psychological diagnostic tests in which the test material is unstructured so that any response will reflect a projection of some aspect of the subject's underlying personality and psychopathology.

pseudocyesis
Included in DSM-IV as one of the somatoform disorders.  It is characterized by a false belief of being pregnant and b y the occurrence of signs of being pregnant, such as abdominal enlargement, breast engorgement, and labor pains.

pseudodementia
A syndrome in which dementia is mimicked or caricatured by a functional psychiatric illness.  Symptoms and response of mental status examination questions are similar to those found in verified cases of dementia.  In pseudodementia, the chief diagnosis to be considered in the differential is depression in an older person vs. cognitive deterioration on the basis of organic brain disease.

psychomotor agitation
Excessive motor activity associated with a feeling of inner tension.  The activity is usually nonproductive and repetitious and consists of such behavior as pacing, fidgeting, wringing of the hands, pulling of clothes, and inability to sit still.

psychomotor retardation
Visible generalized slowing of movements and speech.

psychotic
This term has historically received a number of different definitions, none of which has achieved universal acceptance.  The narrowest definition of psychotic is restricted to delusions or prominent hallucinations, with the hallucinations occurring in the absence of insight into their pathological nature.  A slightly less restrictive definition would also include prominent hallucinations that the individual realizes are hallucinatory experiences.  Broader still is a definition that also includes other positive symptoms of Schizophrenia (i.e., disorganized speech, grossly disorganized or d\\catatonic behavior).  Unlike these definitions based on symptoms, the definition used in DSM-II and ICD-9 was probably far too inclusive and focused on the severity of functional impairment, so that a mental disorder was termed psychotic if it resulted in \"impairment that grossly interferes with the capacity to meet ordinary demands of life\".  Finally, the term has been defined conceptually as a loss of ego boundaries or a gross impairment in reality testing.  Based on their characteristic features, the different disorders in DSM-IV emphasize different aspects of the various definitions of psychotic.

psychotic disorder, shared
Induced psychotic disorder; for example, person A develops a delusion in the context of a close relationship with person B, who has an already established delusion.  The delusion in person A is similar in content to person B's delusion.  One example is folie a deux.

psychotominetic
Literally, mimicking a psychosis.  Used to refer to certain drugs such as LSD or mescaline that may produce psychotic-like states.

Q-sort
A personality assessment technique in which the subject (or some observer) indicates the degree to which a standardized set of descriptive statements actually describes him or her (the subject).  The term reflects the \"sorting\" procedures occasionally used with this technique.

quantitative variable
An object of observation that varies in manner or degree in such a way that it may be measured.

randon sample
A group of subjects selected in such a way that each member of the population from which the sample is derived has an equal or known chance (i.e., probability) of being chosen for the sample.

rationalization
A defense mechanism, operating unconsciously, in which an individual attempts to justify or make consciously tolerable by plausible means, feelings or behavior that otherwise would be intolerable.  Not to be confused with conscious evasion or dissimulation.

reaction formation
A defense mechanism, operating unconsciously, in which a person adopts affects, ideas, and behaviors that are the opposites of impulses harbored either consciously or unconsciously.  For example, excessive moral zeal may be a reaction to strong but repressed asocial impulses.

reality principle
In psychoanalytic theory, the concept that the pleasure principle, which represents the claims of instinctual wishes, is normally modified by the demands and requirements of the external world.  In fact, the reality principle may still work on behalf of the pleasure principle but reflects compromises and allows for the postponement of gratification to a more appropriate time.  The reality principle usually becomes more prominent in the course of development but may be weak in certain psychiatric illnesses and undergo strengthening during treatment.

reality testing
The ability to evaluate the external world objectively and to differentiate adequately between it and the internal world.  Falsification of reality, as with massive denial or projection, indicates a severe disturbance of ego functioning and/or of the perceptual and memory processes upon which it is partly based.

reciprocal inhibition
In behavior therapy, the hypothesis that if anxiety-provoking stimuli occur simultaneously with the inhibition of anxiety (e.g., relaxation), the bond between those stimuli and the anxiety will be weakened.

regression
Partial or symbolic return to earlier patterns of reacting or thinking.  Manifested in a wide variety of circumstances such as normal sleep, play, physical illness, and in many mental disorders.

reinforcement
The strengthening of a response by reward or avoidance of punishment.  This process is central in operant conditioning.

relative risk
The ratio of the disorder (usually incidence of mortality) of those exposed to the disorder to the rate of those not exposed.

reliability
The extent to which the same test or procedure will yield the same result either over time or with different observers.  The most commonly reported reliabilities are: test-retest reliability-the correlation between the first and second test of a number of subjects; split-half reliability-the correlation within a single test of two similar parts of the test; and interrater reliability-the agreement between different individuals scoring the same procedure or observations.

repetition compulsion
In psychoanalytic theory, the impulse to reenact earlier emotional experiences.

repression
A defense mechanism, operating unconsciously, that banishes unacceptable ideas, fantasies, affects, or impulses from consciousness or that keeps out of consciousness what has never been conscious.  Although not subject to voluntary recall, the repressed material may emerge in disguise form.  Often confused with the conscious mechanism of suppression.

residual phase
The phase of an illness that occurs after remission of the florid symptoms or the full syndrome.

resistance
One's conscious or unconscious psychological defense against bringing repressed (unconscious) thoughts into conscious awareness.

respondent conditioning (classical conditioning, Pavlovian conditioning)
Elicitation of a response by a stimulus that normally does not elicit that response.  The response is one that is mediated primarily by the autonomic nervous system (such as salivation or a change in heart rate).  A previously neutral stimulus is repeatedly presented just before an unconditioned stimulus that normally elicits that response.  When the response subsequently occurs in the presence of the previously neutral stimulus, it is called a conditioned response, and the previously neutral stimulus, a conditioned stimulus.

restricted or constricted affect
Mild reduction in the range and intensity of emotional expression.

retardation, mental
A major group of disorders of infancy, childhood, or adolescence characterized by intellectual functioning that is significantly below average (IQ of 70 or below), manifested before the age of 18 by impaired adaptive functioning (below expected performance for age in such areas as social or daily living skills, communication, and self-sufficiency).

retrograde amnesia
Loss of memory of events that occurred before the onset of the etiological condition or agent.

screen memory
A consciously tolerable memory that serves as a cover for an associated memory that would be emotionally painful if recalled.

secondary gain
The external gain derived from any illness, such as personal attention and service, monetary gains, disability benefits, and release from unpleasant responsibilities.

secondary process
In psychoanalytic theory, mental activity and thinking characteristic of the ego and influenced by the demands of the environment.  Characterized by organization, systematization, intellectualization, and similar processes leading to logical thought and action in adult life.

selection bias
The inadvertent selection of a nonrepresentative sample of subjects or observations.  A classic example is a 1936 Literary Digest poll that predicted Landon's election over Roosevelt in which telephone directories were used as the basis for selecting respondents.

separation-individuation
Psychological awareness of one's separateness, described by Margaret Mahler as a phase in the mother-child relationship that follows the symbiotic stage.  In the separation-individuation stage, the child begins to perceive himself or herself as distinct from the mother and develops a sense of individual identity and an image of the self as object.  Mahler described four subphases of the process:  differentiation, practicing, rapprochement (i.e., active approach toward the mother, replacing the relative obliviousness to her that prevailed during the practicing period), and separation-individuation proper (i.e., awareness of discrete identity, separateness, and individuality).

sex
A person's biological status as male, female, or uncertain.  Depending on the circumstances, this determination may be based on the appearance of the external genitalia or on karyotyping.

shaping
Reinforcement of responses in the patient's repertoire that increasingly approximate sought-after behavior.

sick role
An identity adopted by an individual as a \"patient\" that specifies a set of expected behaviors, usually dependent.

sign
An objective manifestation of a pathological condition.  Signs are observed by the examiner rather than reported by the affected individual.

signal anxiety
An ego mechanism that results in activation of defensive operations to protect the ego from being overwhelmed by an excess of excitement.  The anxiety reaction that was originally experienced in a traumatic situation is reproduced in an attenuated form, allowing defenses to be mobilized before the current threat does, in fact, become overwhelming.

significance level
The arbitrarily selected probability level for rejecting the null hypothesis, commonly 0.05 or 0.01.

significant differences
Statistical tests showing that a given difference is not likely to have occurred by chance.  In many behavioral studies, the likelihood of an event occurring less frequently than 1 in 20 times (P < 0.05) is considered the minimal acceptable significance level. The determination that a given difference between two groups is significant can merely serve to identify the likelihood that it was not a chance event.  In no way does this prove that the demonstrated systematic difference is necessarily due to the reasons hypothesized by an investigator.  Systematic factors not considered by the investigator can sometimes be responsible for significant differences.

sleep terror disorder
One of the parasomnias, characterized by panic and confusion when abruptly awakening from sleep.  This usually begins with a scream and is accompanied by intense anxiety.  The person is often confused and disoriented after awakening.  No detailed dream is recalled, and there is amnesia for the episode.  Sleep terrors typically occur during the first third of the major sleep episode.

social adaptation
The ability to live and express oneself according to society's restrictions and cultural demands.

somatic delusion
A delusion whose main content pertains to the appearance or functioning of one's body.

somatic hallucination
A hallucination involving the perception of a physical experience localized within the body (such as a feeling of electricity).  A somatic hallucination is to be distinguished from physical sensations arising from an as-yet undiagnosed general medical condition, from hypochondriacal preoccupation with normal physical sensations, and from a tactile hallucination.

splitting
A mental mechanism in which the self or others are reviewed as all good or all bad, with failure to integrate the positive and negative qualities of self and others into cohesive images.  Often the person alternately idealizes and devalues the same person.

standard deviation (SD)
a mathematical measure of the dispersion or spread of scores clustered about the mean. In any distribution that approximates the normal curve in form, about 65% of the measurements will lie within one SD of the mean, and about 95% will lie within two SDs of the mean.

statistical inference
The process of using a limited sample of data to infer something about a larger population of potentially obtainable data that have not been observed.

stereotyped movements
Repetitive, seemingly driven, and nonfunctional motor behavior (e.g., hand shaking or waving, body rocking, head banging, mouthing of objects, self-biting, picking at skin or body orifices, hitting one's own body).

Stockholm syndrome
A kidnapping or terrorist hostage identifies with and has sympathy for his or her captors on whom he or she is dependent for survival.

stressor, psychosocial
Any life event or life change that may be associated temporally (and perhaps causally) with the onset, occurrence, or exacerbation of a mental disorder.

structural theory
Freud's model of the mental apparatus composed of id, ego, and superego.

stupor
A state of unresponsiveness with immobility and mutism.

subconscious
Obsolete term.  Formerly used to include the preconscious (what can be recalled with effort) and the unconscious.

sublimation
A defense mechanism, operating unconsciously, by which instinctual drives, consciously unacceptable, are diverted into personally and socially acceptable channels.

substitution
A defense mechanism, operating unconsciously, by which an unattainable or unacceptable goal, emotion, or object is replaced by one that is more attainable or acceptable.

suggestibility
Uncritical compliance or acceptance of an idea, belief, or attribute.

suggestion
The process of influencing a patient to accept an idea, belief, or attitude suggested by the therapist.

superego
In psychoanalytic theory, that part of the personality structure associated with ethics, standards, and self-criticism.  It is formed by identification with important and esteemed persons in early life, particularly parents.  The supposed or actual wishes of these significant persons are taken over as part of the child's own standards to help form the conscience.

suppression
The conscious effort to control and conceal unacceptable impulses, thoughts, feelings, or acts.

symbiosis
A mutually reinforcing relationship between two persons who are dependent on each other; a normal characteristic of the relationship between the mother and infant child.

symbolization
A general mechanism in all human thinking by which some mental representation comes to stand for some other thing, class of things, or attribute of something.  This mechanism underlies dream formation and some symptoms, such as conversion reactions, obsessions, and compulsions.  The link between the latent meaning of the symptom and the symbol is usually unconscious.

symptom
A subjective manifestation of a pathological condition.  Symptoms are reported by the affected individual rather than observed by the examiner.

syndrome
A grouping of signs and symptoms, based on their frequent co-occurrence, that may suggest a common underlying pathogenesis, course, familial pattern, or treatment selection.

synesthesia
A condition in which a sensory experience associated with one modality occurs when another modality is stimulated, for example, a sound produces the sensation of a particular color.

syntaxic mode
The mode of perception that forms whole, logical, coherent pictures of reality that can be validated by others.

systematic desensitization
A behavior therapy procedure widely used to modify behaviors associated with phobias.  The procedure involves the construction of a hierarchy of anxiety-producing stimuli by the subject, and gradual presentation of the stimuli until they no longer produce anxiety.

tactile hallucination
A hallucination involving the perception of being touched or of something being under one's skin.  The most common tactile hallucinations are the sensation of electric shocks and formication (the sensation of something creeping or crawling on or under the skin).

tangentiality
Replying to a question in an oblique or irrelevant way.

tardive dyskinesia
Side-effect of antipsychotic medication that involves involuntary movement, including lip smacking and sucking, jaw movements, \"fly catcher\" tongue movements, writhing movements of the extremities and occasional difficulty swallowing.

temperament
Constitutional predisposition to react in a particular way to stimuli.

terminal insomnia
Awakening before one's usual waking time and being unable to return to sleep.

termination
The act of ending or concluding.  In psychotherapy, termination refers to the mutual agreement between patient and therapist to bring therapy to an end.  The idea of termination often occurs to both, but usually it is the therapist who introduces the subject into the session as a possibility to be considered.  In psychoanalytic treatment, the patient's reactions are worked through to completion before the treatment ends.  The early termination that is characteristic of focal psychotherapy and other forms of brief psychotherapy often requires more extensive work with the feelings of loss and separation.

test of significance
A comparison of the observed probability of an event with the predicted probability that is based on calculations deduced from statistical chance distributions of such events.

testamentary capacity
Pertains to the state of mind of an individual at the time he or she writes or executes his or her will.  Generally, to have sufficient testamentary capacity, testators must possess a certain level of understanding of the nature and extent of their property, of the persons who are the natural objects of their bounty, and of the disposition that they are making of their property, and must appreciate these elements in relation to each other and form an orderly desire as to the disposition of their property.

theory
A general statement predicting, explaining, or describing the relationships among a number of constructs.

therapeutic community
A term of British origin, now widely used, for a specially structured mental hospital milieu that encourages patients to function within the range of social norms.

therapeutic window
A well-defined range of blood levels associated with optimal clinical response to antidepressant drugs, such as nortriptyline.  Levels above or below that range are associated with a poor response.

thought broadcasting
The delusion that one's thoughts are being broadcast out loud so that they can be perceived by others.

thought insertion
The delusion that certain of one's thoughts are not one's own but rather are inserted into one's mind.

tic
an involuntary, sudden, rapid, recurrent, nonrhythmic, stereotyped motor movement or vocalization.

tolerance
A characteristic of substance dependence that may be shown by the need for markedly increased amounts of the substance to achieve intoxication or the desired effect, by markedly diminished effect with continued use of the same amount of the substance, or by adequate functioning despite doses or blood levels of the substance that would be expected to produce significant impairment in a casual user.

transference
The unconscious assignment to others of feelings and attitudes that were originally associated with important figures (parents, siblings, etc.) in one's early life.  The transference relationship follows the pattern of its prototype.  The psychiatrist utilizes this phenomenon as a therapeutic tool to help the patient understand emotional problems and their origins.  In the patient-physician relationship, the transference may be negative (hostile) or positive (affectionate).

transitional object
An object, other than the mother, selected by an infant between 4 and 18 months of age for self-soothing and anxiety-reduction.  Examples are a \"security blanket\" or a toy that helps the infant go to sleep.  The transitional object provides an opportunity to master external objects and promotes the differentiation of self from outer world.

transsexualism
Severe gender dysphoria, coupled with a persistent desire for the physical characteristics and social roles that connote the opposite biological sex.

transvestism
Sexual pleasure derived from dressing or masquerading in the clothing of the opposite sex, with the strong wish to appear as a member of the opposite sex.  The sexual origins of transvestism may be unconscious.

type I error
The error that is made when the null hypothesis is true but, as the result of the test of significance, is rejected or declared false.

type II error
The error that is made when the null hypothesis is false but, as a result of the test of significance, is not rejected or declared false.

unconscious
That part of the mind or mental functioning of which the content is only rarely subject to awareness.  It is a repository for data that have never been conscious (primary repression) or that may have been conscious and are later repressed (secondary repression).

undoing
A mental mechanism consisting of behavior that symbolically atones for, makes amends for, or reverses previous thoughts, feelings, or actions.

urophilia
One of the paraphilias, characterized by marked distress over, or acting on, sexual urges that involve urine.

variable
Any characteristic in an experiment that may assume different values.

variance
The square of the standard deviation.

verbigeration
Stereotyped and seemingly meaningless repetition of words or sentences.

visual hallucination
A hallucination involving sight, which may consist of formed images, such as of people, or of unformed images, such as flashes of light.  Visual hallucinations should be distinguished from illusions, which are misperceptions of real external stimuli.

volunteer bias
Bias that may occur when individuals who volunteer for some procedures are not generally representative of the total population.  Self-selected patients who seek out treatment based on newspaper publicity, for example, are likely to do significantly better than random patients who are simply offered the treatment.

voyeurism
Peeping; one of the paraphilias, characterized by marked distress over, or acting on, urges to observe unsuspecting people, usually strangers, who are naked or in the process of disrobing, or who are engaging in sexual activity.

word salad
A mixture of words and phrases that lack comprehensive meaning or logical coherence; commonly seen in schizophrenic states.

zeitgeist
The general intellectual and cultural climate of taste characteristic of an era.

zoophilia
One of the paraphilias, characterized by marked distress over, or acting on, urges to indulge in sexual activity that involves animals.

zygosity
1) Dizygotic: fraternal twins, the product of two fertilized ova. They have the genetic relationship of any two siblings. 2) Monozygotic: identical twins, the product of a single fertilized ovum.