Lithium + L-tryptophan compared with amitriptyline in endogenous depression

Endogenously depressed in-patients were treated for four weeks with either lithium + L-tryptophan (N = 22) or amitriptyline (N = 21) in an open study. Before and weekly during treatment the patients were evaluated by means of Hamilton rating scale, and blood samples were collected for determination of serum concentration of lithium, or amitriptyline and nortriptyline. Both groups responded significantly and the two treatments were not significantly different in antidepressive efficacy. No significant correlation could be demonstrated between clinical improvement and steady-state serum drug levels. From this study it appears that lithium combined with L-tryptophan may be effective in the treatment of endogenous depression.