Cognitive Disorders

Types of cognitive disorder

In the Diagnostic and Statistical Manual of Mental Disorders, 5^th Edition (DSM-5) categories of neurocognitive disorders include delirium and mild and major neurocognitive disorders. There are further classifications of neurocognitive disorders such as Alzheimer’s and Lewy bodies, neurocognitive disorders due to illness or disease such as HIV and Huntington’s, and traumatic brain injury ^[4].

Many cognitive disorders share similar symptoms, often relating to memory, movement, understanding, and emotions ^[2]. Some conditions may affect only a certain area of the brain, causing a specific symptom to emerge or worsen as the condition develops.

With mild neurocognitive disorders, the individual is likely still able to perform tasks and live independently, whereas with a major neurocognitive disorder, the individual will experience significant impairments in their functioning and may require constant support ^[1][5].

Some common types of cognitive disorder include:

Alzheimer’s

Alzheimer’s is a type of dementia and is one of the most common cognitive disorders, affecting around 24 million people worldwide ^[1]. Symptoms can include ^[6]:

• Memory loss
• Repeating the same question or phrase
• Confusion, especially in unfamiliar situations and environments
• Difficulties completing tasks and planning
• Speech and language difficulties
• Low mood and anxiety

Lewy body dementia

Symptoms of Lewy body dementia include ^[6]:

• Hallucinations
• Difficulties with movement
• Dizziness, falls, and fainting
• Trouble sleeping
• Confusion

Vascular dementia

Symptoms of vascular dementia include ^[6]:

• Muscle weakness
• Mobility issues
• Trouble planning and understanding
• Low or labile mood

Frontotemporal dementia

Symptoms of frontotemporal dementia can include ^[7]:

• Difficulties understanding the emotions of others or recognizing social cues
• Inappropriate social behavior
• Social withdrawal
• Difficulties with speech and language

Huntington’s disease

Symptoms of Huntington’s disease can include ^[8]:

• Involuntary movements
• Trouble learning or understanding information
• Mood changes, such as depression and irritability
• Difficulties with speech and language

Amnesia

Symptoms of amnesia can include ^[9]:

• Memory loss of recent or past events
• Difficulty remembering people
• Difficulties with learning new information
• Confusion

Delirium

Symptoms of delirium can include ^[10]:

• Hallucinations and delusions
• Confusion
• Agitation and restlessness
• Sleep disturbances
• Changes in mood
• Memory problems

What causes cognitive disorders?

Cognitive disorders do not have one particular cause and different conditions may develop due to varying circumstances and risk factors.

Genetics

Some cognitive disorders, such as Huntington’s and Frontotemporal dementia may be genetic. Research suggests that a significant percentage of people with these conditions have a relative with the condition ^[7][8].

Biology

Many neurocognitive disorders are degenerative, meaning that they worsen with time. Research suggests that with many degenerative diseases, gray and white matter in the brain is reduced, and there are differences in the volume of certain parts of the brain, indicating that these changes impact the progression of cognitive deterioration ^[2][3].

Environment

Neurocognitive disorders can develop due to issues during pregnancy or childhood, such as malnutrition, exposure to substances, jaundice, and premature birth ^[1].

Injury

Cognitive disorders can develop as a result of a traumatic injury to the brain ^[11]. Depending on the area of the brain that is damaged, this can have an impact on certain aspects of cognitive function. For example, injury to the frontal lobe may impact planning and mood, while an injury to the Broca area can impact speech ^[1].

Stroke

A stroke occurs when there is a disruption in blood supply to the brain, thereby damaging certain areas of the brain. Again, depending on the area of the brain that incurs damage, this can impact cognitive functioning ^[2].

Medical conditions

Certain illnesses and medical treatments can lead to cognitive disorders, such as blood conditions, vitamin deficiency, infections in the brain, meningitis, or hypoxia ^[11].

Substances

Prescribed medications and illicit substances can cause impairments in cognitive functioning. For example, chemotherapy, sedatives, and antihistamines can cause deficits in cognition, as well as alcohol and drug abuse or withdrawal ^[2][12].

Mental illness

Some mental health conditions can lead to cognitive disorders, such as schizophrenia, depression, and attention deficit hyperactivity disorder. These conditions can cause impairments in cognition related to memory, understanding, concentration, and planning ^[12].

How are cognitive disorders diagnosed?

To make a diagnosis of a cognitive disorder, a doctor will undertake a clinical assessment and take a full history of mental and physical health, along with any family health history. They may utilize information from family members as well if required ^[1].

They will ask questions about any changes in functioning, physical health, mood, and behavior to gain a full understanding of the presenting symptoms. To help with their assessment, they may use a medical questionnaire, such as ^[1][3]:

• Mini mental state exam (MMSE)
• General practitioner assessment of cognition (GPCOG)
• Memory impairment screening (MIS)
• Montreal cognitive assessment (MoCA)

These questionnaires can assist in gaining a better understanding of which particular symptoms are emerging, such as loss of memory or orientation to time and place, which can help to rule out or diagnose a specific condition ^[2].

The doctor will also conduct a physical examination to determine whether these symptoms are due to a specific medical condition and may wish to utilize an MRI or CT scan to discover if there are any clear neurological concerns, such as a brain injury, stroke, or tumor ^[3].

How are cognitive disorders treated?

There is no cure for cognitive disorders, but many individuals may still be able to experience a good quality of life with appropriate therapeutic intervention, medication, and supportive care.

Therapy

Individual therapy can help people with mild cognitive disorders to gain a better understanding of their condition and manage the emotions that they are experiencing. People with major cognitive disorders may not benefit from the same therapy if they are lacking in insight and awareness, but may still find support in emotional validation, cognitive therapy, and physical activity ^[3].

Family therapy can be very useful for most types of cognitive disorders, as it can allow family members to discuss their feelings together while receiving support from a professional, as well as gaining a better understanding of the symptoms that their loved one is experiencing and how to best to help them manage ^[1].

Occupational therapy

For many people with a cognitive disorder, occupational therapy is crucial as it can allow them to continue with daily functioning with appropriate support, regardless of their level of cognition, to promote independent living. As well as providing support with daily functioning, an OT can also help to improve and provide social engagement and brain enrichment activities ^[13].

An OT will assess the individual’s abilities and provide alterations to their environment to help improve their functioning. For example, if someone experiences difficulties with their mobility, an OT might adapt their living space to allow for better and safer access and movement ^[1].

Medication

Various medications can be prescribed to help manage certain symptoms of cognitive disorders, although there are no medications that can cure degenerative conditions such as dementia ^[14].

Antidepressants, anxiolytics, anticonvulsants, and antipsychotics may be prescribed to help manage low mood and anxiety, and to reduce symptoms such as hallucinations and delusions that can occur with certain cognitive disorders ^[1].

Cholinesterase inhibitors are often prescribed to people with dementia to help reduce degeneration of the brain and slow the effects of the condition ^[15].

Self-care

Improving and maintaining general wellbeing with physical and mental health can help to prevent or reduce cognitive impairment, by eating well, engaging in regular exercise, maintaining a regular sleep schedule, utilizing relaxation activities, engaging in social interactions, and engaging in brain training exercises and activities ^[1][3]. However, some individuals with cognitive disorders may require assistance with self-care tasks.

Medical treatment

If a cognitive disorder has occurred due to a medical condition, physical health treatment may be required, such as surgery to remove a tumor, medication to treat an infection, or support in reducing substance use.