Use of synthesis inhibitors in defining a role for biogenic amines during imipramine treatment in depressed patients.

Endogenously depressed patients who showed an antidepressant response to the tricyclic drug imipramine continued to show sustained well being after alpha-MPT was added whereas depression returned when small doses of PCPA were added for brief periods. In one patient the antidepressant response to imipramine occurred after pre- and continued treatment with alpha-MPT. Urinary excretion levels of MHPG in one of the patients studied longitudinally did not correspond to the direction of clinical affective state but did reflect anticipated changes during alpha-MPT treatment. Implications are that serotonergic mechanisms are likely involved in the anti-depressant effects of imipramine in man.