The authors assessed the clinical antidepressant effects of L-
tryptophan given alone and in combination with L-dopa in 12 patients with a
diagnosis of primary affective disorder; Preliminary results did not
demonstrate an antidepressant response when L-dopa was combined with
L-tryptophan. Also, the results did not support the catecholamine or
biogenic amine hypotheses of affective disorder.Abstract Teaser