Dopamine receptor stimulation in the treatment of depression: piribedil (ET-495).

ET-495, a putative central dopamine receptor stimulant, was givem to endogenously depressed individuals, all of whom were largely unresponsive to previous drug treatment. The drug exhibited a rapid and, in some cases, a pronounced antidepressant effect. This effect was short-lived, however, and, within a brief period, depression returned accompanied by a consistent syndrome of anger, irritability, hostility and poor temper control. In one individual with a bipolar history, the induction of a paranoid psychosis and auditory hallucinosis occurred. While the data suggests a role for dopamine in the symptomatic relief of depression in man, they also imply that this monoamine cannot, in and of itself, be considered as the primum movens in either the action of other (established) antidepressant drugs, or as underlying depressive illness.