A. The predominant disturbance is a disturbance in mood, with at least two of the associated symptoms listed in criterion B for manic or major depressive episode.
B. No clouding of consciousness, as in Delirium; no significant loss of intellectual abilities, as in Dementia; no predominant delusions or hallucinations, as in Organic Delusional Syndrome or Organic Hallucinosis.
C. Evidence, from the history, physical examination, or laboratory tests, of a specific organic factor that is judged to be etiologically related to the disturbance.
In Affective disorders, no specific organic factor can be demonstrated. When an affective episode follows the taking of a psychoactive substance, such as reserpine, the casual relationship between the ingestion of the substance and the affective disturbance may not be clear. A history of previous Affective Disorder in the individual or in family members suggests that the substance merely triggered an Affective Disorder in an individual who was particularly vulnerable to the organic factor. On the other hand, the absence of a history of previous Affective Disorder in the individual or family members suggests an Organic Affective Syndrome.
In Organic Personality Syndrome, there may be a disturbance of mood, but it is not as prominent as the change in personality.