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Organic Personality Syndrome

Synonyms of Organic Personality Syndrome

  • Personality Syndrome, Organic

Disorder Subdivisions

  • No subdivisions found.

General Discussion

Organic personality syndrome or organic mental syndrome is a mental disorder characterized by a short-term or long-term personality disturbance largely due to brain dysfunction. The ability to reason, remember, imagine, and learn may not be affected, but the individual's judgment may be so poor that continual supervision may be necessary. Left unattended, he or she may behave in ways that could cause difficult or dangerous problems.


In Organic Personality Syndrome, behavior changes and character traits are either exaggerated or at least different from usual. Symptoms usually show themselves in one of three basic patterns depending on the nature and location of the brain dysfunction.

The first and most common pattern is characterized by emotional instability, faulty social judgment, possible belligerence and/or an over-reactive temper. The person may engage in inappropriate social behavior without regard for the consequences (e.g. sexual indiscretions). The second pattern may include significant signs of apathy and indifference. The person has no concern for, or interest in, his or her immediate environment or former customary hobbies. Both of these patterns may be caused by damage to the frontal lobes of the brain (frontal lobe syndromes). The third pattern of behavior, seen in some disorders affecting the temporal lobe, is marked by a strong tendency to be humorless and overly redundant in both speech and writing, and, not infrequently, by overzealous religious devotion. Occasionally, the person may show extreme rage. One of the major changes in this behavior may be unreasonable suspiciousness or paranoid ideas. If the main symptom is outbursts of aggression or rage, the patient may be labeled as an "Explosive Type".


There are several possible causes for Organic Personality Syndrome. Frequently it is the consequence of structural brain damage from neoplasms (tumors), head trauma, or cerebrovascular disease involving the upper part of the brain and its blood vessels. Less commonly, it may be caused by endocrine disorders such as thyroid and adrenocortical (outer part of adrenal gland) disease, or by ingesting certain psychoactive substances (drugs that affect the mind or behavior). The syndrome may be of short duration if caused by medications, drug abuse, or certain types of tumors that are surgically removed. It may be of long duration if it is secondary to structural brain damage.

Affected Populations

Organic Personality Syndrome is a prevalent disorder that affects males and females of all ages in equal numbers. It is often a symptom of an underlying disease or condition.

Related Disorders

Symptoms of the following disorders can be similar to those of Organic Personality Syndrome. However, personality changes can occur in many disorders that are not organic in origin. Psychiatric and/or neurological consultation should be sought to determine the cause of any serious or prolonged change in behavior.

Schizophrenia and delusional, mood, and impulse control disorders are mental illnesses in which marked personality changes are common but which are not related to Organic Personality Syndrome. (For more information on this disorder, choose "Schizophrenia" as your search term in the Rare Disease Database.)

The major symptoms of Antisocial Personality Disorder usually manifest before the age of fifteen. These include behaviors which exhibit little concern for the rights of others, excessive drinking, and fighting. (For more information on this disorder, choose "Antisocial Personality Disorder" as your search term in the Rare Disease Database.)

Attention-Deficit Hyperactivity Disorder (ADHD) is a condition usually caused by abnormalities of the central nervous system and often accompanied by neurological disorders such as cerebral palsy, epilepsy, and Tourette syndrome. ADHD features unusual degrees of inattention, impulsiveness, and physical activity. It usually starts at a young age, half the time before the age of 4. (For more information on these disorders, choose "Attention-Deficit Hyperactivity", "Cerebral Palsy", "epilepsy", or "Tourette Syndrome" as your search term in the Rare Disease Database.)

The following disorders may be the primary underlying cause of Organic Personality Syndrome. They are not necessary for a differential diagnosis:

Huntington's Chorea (also known as Huntington's Disease) is an inherited, progressively degenerative neurological illness leading to personality changes, loss of motor control, loss of memory, and eventual loss of mental capability. (For more information on this disorder, choose "Huntington's Disease" as your search term in the Rare Disease Database.)

Temporal Lobe Epilepsy (also known as Psychomotor Epilepsy) is a central nervous system disorder originating in the temporal lobe area of the brain. It is characterized by partial seizures, impairment of consciousness, strange behavior, hallucinations that may involve odor, and visual perceptions. Organic Personality Syndrome may occur between seizures. (For more information on this disorder, choose "Epilepsy" as your search term in the Rare Disease Database.)

Standard Therapies

Treatment of Organic Personality Syndrome depends upon the cause. If it is due to medication or drug abuse, once the cause is identified, corrective action can be taken and the person's behavior usually returns to normal. If it is due to a brain tumor (neoplasm), much depends on the tumor type, the patient's age, tumor location, and success of therapy. Surgery may be effective, and in some cases patients recover with little or no permanent change in their intellectual abilities and quality of life. If the Organic Personality Syndrome is due to another underlying neurological disorder, appropriate treatment for that disorder may be helpful.

Investigational Therapies

Some research has been done on the effectiveness of certain antidepressant drugs. In the cases tested, patients had Organic Personality Syndrome with no other underlying neurological diseases, combined with depression. Many patients improved on antidepressant drugs and remission occurred in some patients.

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010

For information about clinical trials sponsored by private sources, contact:

Organic Personality Syndrome Resources



Comprehensive Textbook of Psychiatry. 5th ed.: Harold I Kaplan & Benjamin J. Sadock eds.; Williams & Wilkins, 1989. Pp. 599-641.

Psychiatric Disorders in Children and Adolescents After Severe Traumatic Brain Injury: A Controlled Study. J. E. Max, et al. J Am Acad Child Adolesc Psychiatry (March 1998, 37 (8)). Pp. 832-40.

Treatment of Organic Personality Syndrome with Low-Dose Trazodone. C. A. Tejera, et al., J Clin Psychiatry (August 1995, 56 (8)). Pp. 374-75.

Neuropsychological and Neuropsychiatric Findings in Right Hemisphere Damaged Patients. N. Motomura, et al., Japan J Psychiatry Neurol (December 1988, 42 (4)). Pp. 747-52.

Cognitive Outcome and Quality of Life One Year After Subarachnoid Haemorrhage, P. McKenna, et al., Neurosurgery (March 1989, issue 24 (3)). Pp. 361-367.

National Survey of Patterns of Care for Brain-Tumor Patients, M.S. Mahaley, Jr, et al., J Neurosurg (December 1989, issue 71 (6)). Pp. 826-836.


The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.

Report last updated: 2007/08/08 00:00:00 GMT+0

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