Organic mental disorders

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Organic mental disorders
Classification and external resources

An organic mental disorder (OMD), also known as organic brain syndrome or chronic organic brain syndrome, is a form of decreased mental function due to a medical or physical disease, rather than a psychiatric illness. This differs from dementia.[1] While mental or behavioral abnormalities related to the dysfunction can be permanent,[2] treating the disease early may prevent permanent damage in addition to fully restoring mental functions. An organic cause to brain dysfunction is suspected when there is no indication of a clearly defined psychiatric or "inorganic" cause, such as a mood disorder.[3]

Now the DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision) has broken up the diagnoses that once fell under the diagnostic category organic mental disorder into three categories: delirium, dementia, and amnestic.[3]

Organic brain syndrome can be divided into 2 major subgroups: acute (delirium or acute confusional state) and chronic (dementia). A third entity, encephalopathy (subacute organic brain syndrome), denotes a gray zone between delirium and dementia; its early course may fluctuate, but it is often persistent and progressive.[4] Damage to brain functioning could be due not only to organic (physical) injury (a severe blow to the head, stroke, chemical and toxic exposures, organic brain disease, substance abuse, etc.) and also to non-organic means such as severe deprivation, abuse, neglect, and severe psychological trauma.[5]


Symptoms depend on the cause of the OMD. Confusion, memory impairment, delirium, dementia, judgment, logical function and agitation are some common symptoms of OMD.

Associated conditions[edit]

  • Brain injury caused by trauma
    • Bleeding into the brain (intracerebral hemorrhage)
    • Bleeding into the space around the brain (subarachnoid hemorrhage)
    • Blood clot inside the skull causing pressure on brain (subdural hematoma)
    • Concussion
  • Breathing conditions
  • Cardiovascular disorders
  • Degenerative disorders
  • Dementia due to metabolic causes
  • Drug and alcohol-related conditions
    • Alcohol withdrawal state
    • Intoxication from drug or alcohol use
    • Wernicke-Korsakoff syndrome (a long-term effect of excessive alcohol consumption or malnutrition)
    • Withdrawal from drugs (especially sedative-hypnotics and corticosteroids)
  • Infections
    • Any sudden onset (acute) or long-term (chronic) infection
    • Blood poisoning (septicemia)
    • Brain infection (encephalitis)
    • Meningitis (infection of the lining of the brain and spinal cord)
    • Prion infections such as mad cow disease
    • Late-stage syphilis
  • Other medical disorders
    • Cancer
    • Kidney disease
    • Liver disease
    • Thyroid disease (high or low)
    • Vitamin deficiency (B1, B12, or folate)[1]
  • Lithium toxicity can cause permanent organic brain damage[6]
  • Accumulation of heavy metals in the brains


Treatment depends on which disorder is involved in OMD.


Some disorders are short-term and treatable, but many are long-term or get worse over time.[1]

Alternative names[edit]


  1. ^ a b c "Organic brain syndrome: MedlinePlus Medical Encyclopedia". Retrieved 2012-10-12.
  2. ^ "Organic mental disorders". Retrieved 2012-10-12.
  3. ^ a b "Organic Psychosis - Medical Disability Guidelines". Retrieved 2012-10-12.
  4. ^ "Delirium, Dementia, and Amnesia in Emergency Medicine". Retrieved 2012-10-12.
  5. ^ "Differences between psychological and neuropsychological evaluation". Archived from the original on 2012-05-09. Retrieved 2012-10-12.
  6. ^ "A Case of Lithium Poisoning?, Australian and New Zealand Journal of Psychiatry, Informa Healthcare". 1970-01-01. Retrieved 2012-10-12.

External links[edit]