The DSM-5 Guide to Bipolar Disorders

Bipolar disorders are defined by extreme mood swings, including mania or hypomania (which include elevated mood and energy levels) and depression (characterized by low mood and energy levels). These mood swings affect daily life, work, and personal relationships. While their severity and duration vary, they often require clinical attention.

What Are Bipolar Disorders?

Bipolar disorders are a group of mood disorders characterized by significant and extreme mood, energy, and activity level changes^[1]. They are classified into three types: bipolar I, bipolar II, and cyclothymic disorder, each with a different intensity and pattern of mood episodes.

1. Bipolar I disorder: This must include at least one manic episode lasting one week or longer. Depressive episodes may occur but are not required for diagnosis. Manic episodes in bipolar I are severe and can cause significant impairment in daily functioning. Some cases may result in psychosis and may require hospitalization.
2. Bipolar II disorder: This involves at least one hypomanic episode (which is less severe than mania) and at least one major depressive episode. In bipolar II disorder, the depressive episodes are often more prominent and can cause significant impairment, while hypomanic episodes are less disruptive.
3. Cyclothymic disorder: Also known as cyclothymia, this involves frequent hypomanic and depressive symptoms for at least 2 years, but it does not meet the criteria for full-blown hypomanic or depressive episodes. Although less severe, the mood swings still affect daily life.

DSM-5 Diagnostic Criteria for Bipolar Disorders

To be diagnosed with bipolar disorder, a person must have had at least one episode of mania or hypomania. DSM-5 criteria for bipolar disorder are based on manic, hypomanic, and depressive episodes. Below is an outline of the criteria for bipolar disorder:

Manic and Hypomanic Episodes

A manic episode is a distinct period of abnormally elevated, expansive, or irritable mood with increased activity or energy lasting at least one week (or any duration if hospitalization is required)^[1]. A hypomanic episode is a distinct period of abnormally elevated or irritable mood with increased activity or energy lasting at least four consecutive days. During a manic or hypomanic episode, three (or more) of the following symptoms must be present:

1. Inflated self-esteem or grandiosity
2. Decreased need for sleep (e.g., feeling rested after only 3 hours of sleep)
3. More talkative than usual or pressure to keep talking
4. Easily drawn to unimportant or irrelevant stimuli
5. Racing thoughts
6. Increased goal-directed activity (either socially, at work or school, or sexually) or physical restlessness
7. Excessive involvement in risky activities (e.g., unrestrained spending sprees, sexual indiscretions, or foolish business investments)

In manic episodes, the mood disturbance is sufficiently severe to cause marked impairment in social or occupational functioning or necessitate hospitalization to prevent harm. Conversely, in hypomanic episodes, the mood disturbance is noticeable by others, but it does not cause significant impairment in social or occupational functioning and does not require hospitalization.

Depressive Episode

A major depressive episode is a period of depressed mood or loss of interest or pleasure in almost all activities, which lasts at least two weeks. According to the DSM-5, a person must experience five (or more) of these depressive symptoms in two weeks (and at least one of the symptoms must be depressed mood or loss of interest/pleasure):

• Depressed mood most of the day (feeling sad, empty, or hopeless)
• Markedly diminished interest or pleasure in all or most activities
• Weight loss or gain or decrease/increase in appetite
• Insomnia or excessive sleeping
• Restlessness or slowed movements
• Fatigue or loss of energy
• Feelings of worthlessness or excessive guilt
• Difficulty concentrating or indecisiveness
• Thoughts of death, suicidal ideation, or a suicide attempt

These depressive symptoms cause significant distress or impairment in social, occupational, or other areas of functioning.

Mixed Episodes and Rapid Cycling

In the DSM-5, mixed episodes and rapid cycling are essential concepts in bipolar disorders, as they represent unique patterns of mood episodes that can occur in either bipolar I or bipolar II disorder.

A mixed episode is when an individual experiences both manic/hypomanic and depressive symptoms at the same time or in rapid succession. In the DSM-5, this is called “mixed features” and can occur during a manic, hypomanic, or depressive episode. For example, a person may feel elevated or energized (manic/hypomanic) and at the same time feel hopeless, guilty, or fatigued (depressed).

The DSM-5 specifies that if three or more depressive symptoms are present during a manic or hypomanic episode or three or more manic or hypomanic symptoms are present during a depressive episode, it is considered to have mixed features^[2].

Rapid cycling occurs when four or more episodes of mood disturbance (manic, hypomanic, or depressive) occur within 12 months^[1]. These episodes can be of any type, but the hallmark of rapid cycling is the speed at which mood shifts occur. The episodes may alternate between depressive and manic/hypomanic states or consecutive episodes of the same polarity (e.g., multiple depressive episodes).

Episodes can be triggered by stress, treatment changes, or non-adherence to medication, but the exact cause of rapid cycling is not always clear. Rapid cycling makes the course of the disorder more severe and may lead to more episodes, making long-term management more challenging.

Changes from DSM-IV to DSM-5

Alterations were made in the DSM-5 regarding the bipolar disorder diagnostic criteria to improve clarity and provide more accurate diagnoses. The following sections outline the main changes to the bipolar diagnosis criteria.

Revised Definition of Bipolar II Disorder

In the DSM-IV, it was possible to be diagnosed with bipolar II disorder by experiencing at least one hypomanic episode and at least one major depressive episode without a manic episode.

In the DSM-5, the diagnosis criteria for bipolar II disorder remains relatively unchanged. However, the aspect of at least one full manic episode not being present is more clearly stated, and it highlights that bipolar II disorder has episodes of hypomania and depression but not a manic episode.

Introduction of “Mixed Features” in Bipolar I and II

The DSM-IV recognizes mixed episodes as a unique diagnosis that must accompany an episode of mania or depression. The DSM-5 introduced the concept of mixed features within bipolar disorder, and mixed episodes were removed as a distinct diagnosis^[2]. Therefore, a hypomanic, manic, or major depressive episode can have mixed features, which is when three or more symptoms of the opposite mood polarity are present.

Introduction of “Rapid Cycling” as a Specifier

Rapid cycling was a course specifier for bipolar I and bipolar II in the DSM-IV but was not well defined. Rapid cycling is also a course specifier for bipolar I and bipolar II in the DSM-5. However, the DSM-5 says four or more episodes of mood disturbance (mania, hypomania, or depression) in 12 months are required to meet the criteria for rapid cycling. This is to make the diagnosis more specific and consistent.

Criteria for Hypomanic Episodes

The DSM-IV criteria for a hypomanic episode were similar to those for mania but less severe and with no marked impairment in functioning. However, the DSM-IV left some ambiguity about the impact of hypomania on functioning. In the DSM-5, the criteria for hypomanic episodes were refined to say there is no significant impairment in social or occupational functioning. A hypomanic episode explicitly does not cause marked impairment in functioning or hospitalization, distinguishing it from a manic episode.

Clarification on the Duration of Mood Episodes

The DSM-IV stated that manic episodes must last at least one week, but the exact duration of hypomanic episodes was not specified in relation to functioning. According to the DSM-5, hypomanic episodes must last four consecutive days, and the individual must not have any significant impairment. Manic episodes must still last at least one week (or any duration if the individual is hospitalized).

Differential Diagnosis and Comorbidities

A differential diagnosis compares two or more medical conditions that may have similar symptoms. It’s vital in the context of bipolar disorder because its symptoms can overlap with many other psychiatric and medical conditions^[3].

Bipolar disorder is characterized by mood fluctuations that include manic, hypomanic, and depressive episodes. However, several other mental health conditions can present with similar symptoms and cause confusion or misdiagnosis. Some of these conditions are borderline personality disorder (BPD), major depressive disorder (MDD), schizoaffective disorder, and attention-deficit hyperactivity disorder (ADHD)^[3].

There are several reasons why differential diagnosis is essential. These include:

• Symptom overlap: Bipolar disorder shares symptoms with other psychiatric conditions, like depression, anxiety, and certain personality disorders. For example, the depressive episodes of BD can look like major depressive disorder, and the manic episodes can be mistaken for mood or psychotic disorders.
• Treatment implications: Misdiagnosis can lead to ineffective or inappropriate bipolar disorder treatment. For example, treating a person with BD with antidepressants alone (without a mood stabilizer or antipsychotic) can trigger manic symptoms and worsen the course of the illness. Treating a patient for another condition without addressing the underlying bipolar symptoms can delay proper care and worsen patient outcomes.
• Medication management: Proper diagnosis means correct pharmacological interventions. Bipolar disorder often requires mood stabilizers (e.g., lithium), antipsychotics, or anticonvulsants, and the wrong diagnosis can lead to the prescription of the wrong medications that can cause side effects or worsen the condition.
• Prognosis and functionality: Accurate diagnosis and treatment are key to managing the long-term course of the mental disorder and functionality in areas like work, relationships, and overall quality of life. Bipolar disorder can be severely debilitating if not treated properly.

Bipolar disorder is often comorbid with many other psychiatric and medical conditions. These conditions can complicate the disorder’s diagnosis, treatment, and prognosis. Some of the most common comorbidities are:

• Anxiety disorders: Anxiety disorders, especially generalized anxiety disorder (GAD), panic disorder, and social anxiety disorder, are prevalent in people with BD. Anxiety symptoms can overlap with mood episodes, and the presence of both anxiety and bipolar disorder can worsen mood symptoms, impair functioning, and complicate bipolar disorder treatment choices.
• Obsessive-compulsive disorder (OCD): OCD often coexists with bipolar disorder, especially during depressive episodes. People with bipolar disorder and OCD may have intrusive thoughts and compulsive behaviors that can worsen distress and impairment. Managing both medical conditions requires a combined approach that addresses the mood symptoms and the OCD.
• Attention-deficit/hyperactivity disorder (ADHD): ADHD often co-occurs with bipolar disorder, especially in younger individuals. Both have symptoms of impulsivity, hyperactivity, and inattention, but when together, they complicate diagnosis and treatment. When ADHD is present with bipolar disorder, it requires a more tailored treatment plan that addresses both.
• Sleep disorders: Sleep disturbances (insomnia, hypersomnia, or irregular sleep-wake cycles) are common in bipolar disorder. Manic episodes are often characterized by a decreased need for sleep, and depressive episodes are characterized by hypersomnia or excessive sleeping. These sleep disturbances can worsen mood symptoms and overall quality of life. Proper management of sleep issues is key to stabilizing mood.
• Substance use disorders: Substance use disorders (as with alcohol, drugs, or nicotine) are common in individuals with bipolar disorder, especially during manic episodes. This comorbidity can lead to poor treatment adherence, treatment resistance, and worse long-term outcomes. Substance abuse can also worsen mood instability and increase suicidal risk.