Neurotransmitter hypotheses of depression. Research update.

Recent research on the amine neurotransmitter hypotheses of depression has moved toward comparative analysis of presynaptic neurotransmitter release and postsynaptic receptor function. Although no single pathognomonic defect has been identified in major depression, alterations in these systems have been identified in subgroups of depressed patients. Therapeutic effects of antidepressant drugs may be linked to adaptive changes in brain neurotransmitter release and receptor function.