An older and nearly obsolete category originally created to distinguish physiological (termed exogenous or organic) causes of mental impairment from psychiatric (termed endogenous or functional) causes. The term was abandoned in dsm-iv because it was judged to incorrectly imply that “nonorganic” mental disorders did not have a biological basis.
Transient or permanent dysfunction of the brain, caused by a disturbance of physio- logic functioning of brain tissue at any level of organization—structural, hormonal, biochemical, electrical, etc. DSM-llI-R recognizes the following organic brain syndromes: delirium, dementia, amnestic syndrome, organic anxiety syndrome, organic delusional syndrome, organic hallucinosis, organic mood syndrome, organic personality syndrome, and mixed or atypical brain syndrome, all of which are classified according to etiology or pathophysiology. Causes are associated with aging, toxic substances, or a variety of physical disorders.
A disorder that is caused by a physical change in brain tissue or brain functioning. Withdrawal syndrome from drugs or Alzheimer’s disease are examples of organic psychosis.