Clinical evaluation of 5-hydroxy-L-tryptophan as an antidepressant drug

Effectiveness of 5-hydroxy-L-trytophan as an antidepressant drug was studied with 59 patients with depressive symptoms using Rating Scale for Depression made by Clinico-Psychopharmacology Research Group in Japan for a preparatory step of a double blind clinical study of 5-hydroxy-L-tryptophan treatment of depression. A daily dose of 150--300 mg of 5-hydroxyl-L-tryptophan was administered for three weeks. Favorable responses were observed in 40 patients (67.8%), of whom 13 patients were markedly improved. These effects were noticed in 32 patients (80% of the improved patients) within a week of the treatment. Analysis of General Improvement Rating in the various subtypes of depressive symptoms indicated that endogenous depression and involutional or senile depression were the preferable indication of 5-hydroxy-L-tryptophan loading. The main side effects of 5-hydroxy-L-tryptophan were gastrointestinal disturbances which were minimized by the simultaneous administration of metoclopromide or trihexyphenidyl.