Neurocognitive disorder
Organic mental disorder (OMS); Organic brain syndromeNeurocognitive disorder is a general term that describes decreased mental function due to a medical disease other than a psychiatric illness.
Neurocognitive disorders are grouped into three subcategories:
- Delirium.
Delirium
Delirium is sudden severe confusion due to rapid changes in brain function that can occur with physical or mental illness.
Read Article Now Book Mark Article - Mild neurocognitive disorder - some decreased mental function, but able to stay independent and do daily tasks.
- Major neurocognitive disorder - decreased mental function and loss of ability to do daily tasks. Also called dementia.
Dementia
Dementia is a loss of brain function that occurs with certain diseases. It affects one or more brain functions such as memory, thinking, language, j...
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Causes
Listed below are conditions associated with neurocognitive disorder.
BRAIN INJURY CAUSED BY TRAUMA
- Bleeding into the brain (intracerebral hemorrhage)
- Bleeding into the space around the brain (subarachnoid hemorrhage)
Subarachnoid hemorrhage
Subarachnoid hemorrhage is bleeding in the area between the brain and the thin tissues that cover the brain. This area is called the subarachnoid sp...
Read Article Now Book Mark Article - Blood clot inside the skull but outside the brain and its covering, which may cause pressure on the brain (subdural hematoma or epidural hematoma)
Subdural hematoma
A chronic subdural hematoma is an "old" collection of blood and blood breakdown products between the surface of the brain and its outermost covering ...
Read Article Now Book Mark ArticleEpidural hematoma
An epidural hematoma (EDH) is bleeding between the inside of the skull and the outer covering of the brain (called the dura mater).
Read Article Now Book Mark Article - Concussion
Concussion
A traumatic brain injury (TBI) can occur when the head hits an object, or a moving object strikes the head. There are three types of TBI:Mild TBI, a...
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BREATHING CONDITIONS
- Low oxygen in the body (hypoxia)
- High carbon dioxide level in the body (hypercapnia)
CARDIOVASCULAR DISORDERS
- Dementia due to many strokes (multi-infarct dementia)
Multi-infarct dementia
Dementia is a loss of brain function that occurs with certain diseases. It affects one or more brain functions such as memory, thinking, language, j...
Read Article Now Book Mark Article - Heart infections (endocarditis, myocarditis)
Endocarditis
Endocarditis is inflammation of the inside lining of the heart chambers and heart valves (endocardium). It is caused by a bacterial or, rarely, a fu...
Read Article Now Book Mark ArticleMyocarditis
Myocarditis is inflammation of the heart muscle. The condition is called pediatric myocarditis when it occurs in children.
Read Article Now Book Mark Article - Stroke
Stroke
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...
Read Article Now Book Mark Article - Transient ischemic attack (TIA)
Transient ischemic attack
A transient ischemic attack (TIA) occurs when blood flow to a part of the brain stops for a brief time. A person will have stroke-like symptoms for ...
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DEGENERATIVE DISORDERS
- Alzheimer disease (also called senile dementia, Alzheimer type)
Alzheimer disease
Dementia is a loss of brain function that occurs with certain diseases. Alzheimer disease (AD) is the most common form of dementia. It affects memo...
Read Article Now Book Mark Article - Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease (CJD) is a form of brain damage that leads to a rapid decrease in movement and loss of mental function.
Read Article Now Book Mark Article - Diffuse Lewy body disease
- Huntington disease
Huntington disease
Huntington disease (HD) is a genetic disorder in which nerve cells in certain parts of the brain waste away, or degenerate. The disease is passed do...
Read Article Now Book Mark Article - Normal pressure hydrocephalus
Normal pressure hydrocephalus
Hydrocephalus is a buildup of spinal fluid inside the fluid chambers of the brain. Hydrocephalus means "water on the brain. "Normal pressure hydroce...
Read Article Now Book Mark Article - Parkinson disease
Parkinson disease
Parkinson disease results from certain brain cells dying. These cells help control movement and coordination. The disease leads to shaking (tremors...
Read Article Now Book Mark Article - Pick disease
Pick disease
Frontotemporal dementia (FTD) is a rare form of dementia that is similar to Alzheimer disease, except that it tends to affect only certain areas of t...
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AUTOIMMUNE DISEASES
- Multiple sclerosis
Multiple sclerosis
Multiple sclerosis (MS) is an autoimmune disease that affects the brain and spinal cord (central nervous system).
Read Article Now Book Mark Article - Autoimmune encephalitis
DEMENTIA DUE TO METABOLIC CAUSES
DEMENTIA DUE TO METABOLIC CAUSES
Dementia is loss of brain function that occurs with certain diseases. Dementia may also be referred to as major neurocognitive disorder. Dementia du...
Read Article Now Book Mark Article- Kidney disease
Kidney disease
Chronic kidney disease is the slow loss of kidney function over time. The main job of the kidneys is to remove wastes and excess water from the body...
Read Article Now Book Mark Article - Liver disease
Liver disease
The term "liver disease" applies to many conditions that stop the liver from working or prevent it from functioning well. Abdominal pain or swelling...
Read Article Now Book Mark Article - Thyroid disease (hyperthyroidism or hypothyroidism)
Hyperthyroidism
Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.
Read Article Now Book Mark ArticleHypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....
Read Article Now Book Mark Article - Vitamin deficiency (B1, B12, or folate)
DRUG AND ALCOHOL-RELATED CONDITIONS
- Alcohol withdrawal state
Alcohol withdrawal state
Alcohol withdrawal refers to symptoms that may occur when a person who has been drinking too much alcohol on a regular basis suddenly stops drinking ...
Read Article Now Book Mark Article - Intoxication from drug or alcohol use
Alcohol use
Alcohol use disorder is when your drinking causes serious problems in your life, yet you keep drinking. You may also need more and more alcohol to f...
Read Article Now Book Mark Article - Medicine effect, such as corticosteroids, sedative-hypnotics, antihistamines, and antidepressants
- Wernicke-Korsakoff syndrome, a long-term effect of deficiency of thiamine (vitamin B1)
Wernicke-Korsakoff syndrome
Wernicke-Korsakoff syndrome is a brain disorder due to vitamin B1 (thiamine) deficiency.
Read Article Now Book Mark Article - Withdrawal from medicines, such as sedative-hypnotics and corticosteroids
INFECTIONS
- Any sudden onset (acute) or long-term (chronic) infection
Acute
Acute means sudden. Acute symptoms appear, change, or worsen rapidly. It is the opposite of chronic.
Read Article Now Book Mark ArticleChronic
Chronic refers to something that continues over an extended period of time. A chronic condition is usually long-lasting and does not easily or quick...
Read Article Now Book Mark Article - Blood poisoning (septicemia)
Septicemia
Septicemia is bacteria in the blood (bacteremia) that often occurs with severe infections. Also called sepsis, septicemia is a serious, life-threate...
Read Article Now Book Mark Article - Brain infection (encephalitis)
Encephalitis
Encephalitis is irritation and swelling (inflammation) of the brain, most often due to infections.
Read Article Now Book Mark Article - Meningitis (infection of the lining of the brain and spinal cord)
Meningitis
Meningitis is an infection of the membranes covering the brain and spinal cord. This covering is called the meninges.
Read Article Now Book Mark Article - Prion infections, such as mad cow disease
- Late-stage syphilis
Complications of cancer and cancer treatment with chemotherapy and radiation therapy to the brain can also lead to neurocognitive disorder.
Other conditions that may mimic neurocognitive disorder include:
- Depression
Depression
Depression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for shor...
Read Article Now Book Mark Article - Neurosis
- Psychosis
Psychosis
Psychosis occurs when a person loses contact with reality. The person may: Have false beliefs about what is taking place, or who one is (delusions)S...
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Symptoms
Symptoms can differ based on the disease. In general, neurocognitive disorder causes:
- Agitation
Agitation
Agitation is an unpleasant state of extreme arousal. An agitated person may feel stirred up, excited, tense, confused, or irritable.
Read Article Now Book Mark Article - Confusion
Confusion
Confusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...
Read Article Now Book Mark Article - Long-term loss of brain function (mild cognitive impairment or dementia)
- Severe, short-term loss of brain function (delirium)
Exams and Tests
Tests depend on the disorder, but may include:
- Blood tests
- Neuropsychological testing
- Electroencephalogram (EEG)
Electroencephalogram
An electroencephalogram (EEG) is a test to measure the electrical activity of the brain.
Read Article Now Book Mark Article - Head CT scan
Head CT scan
A head computed tomography (CT) scan uses many x-rays to create pictures of the head, including the skull, brain, eye sockets, and sinuses.
Read Article Now Book Mark Article - Head MRI
Head MRI
A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...
Read Article Now Book Mark Article - Lumbar puncture (spinal tap)
Lumbar puncture
Cerebrospinal fluid (CSF) collection is a test to look at the fluid that surrounds the brain and spinal cord. CSF acts as a cushion, protecting the b...
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Treatment
Treatment depends on the underlying condition. Many conditions are treated mainly with rehabilitation and supportive care to help the person with activities lost due to areas where brain function is affected.
Medicines may be needed to reduce aggressive behaviors that can occur with some of the conditions.
Outlook (Prognosis)
Some disorders are short-term and reversible. But many are long-term or get worse over time.
Possible Complications
People with neurocognitive disorder often lose the ability to interact with others or function on their own.
When to Contact a Medical Professional
Contact your health care provider if:
- You have been diagnosed with neurocognitive disorder and you are uncertain about the exact disorder.
- You have symptoms of this condition.
- You have been diagnosed with neurocognitive disorder and your symptoms become worse.
References
Beck BJ, Smith FA, Stern TA. Mental disorders due to another medical condition. In: Stern TA, Wilens TE, Fava M, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 3rd ed. Philadelphia, PA: Elsevier; 2025:chap 21.
Inouye SK. Delirium and changes in mental status. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 361.
Knopman DS. Cognitive impairment and dementia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 371.
Merrick ST, Glesby MJ. Systemic manifestations of HIV/AIDS. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 359.
Sorg EM, Jankauskaite G, Jacobs J. Psychiatric co-morbidities and complications of cancer and cancer treatment. In: Stern TA, Wilens TE, Fava M, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 3rd ed. Philadelphia, PA: Elsevier; 2025:chap 46.
Review Date: 3/31/2024
Reviewed By: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School at Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.