Tricyclic antidepressants such as imipramine or ami- triptyline are most frequently used in the treatment of endogenous depre~sion.l-~ Their ability to inhibit the uptake of norepinephrine (NE) and 5-hydroxytryptamine (5-HT) into the presynaptic nerve terminal has generally been predictive of antidepressant action in man.4*6 However, these drugs have undesirable anticholinergic6 or cardiotoxic side effects7+ that seem to be related to their tricyclic structure. ...