ABSTRACT
Although genetic factors play a major, unquestionable role in the etiology of bipolar disorder, the biochemical abnormalities underlying the predisposition to and the pathophysiology of this complex and intriguing neuropsychiatric disorder remain to be fully elucidated. The brain systems that have heretofore received the greatest attention in neurobiologic studies of these illnesses have been the monoaminergic neurotransmitter systems, which were implicated by the following observations:
1. Effective antidepressant drugs exert their primary biochemical effects by regulating intrasynaptic concentrations of serotonin and norepinephrine
2. Antihypertensives that deplete these monoamines sometimes precipitate depressive episodes in susceptible individuals.
