THE EFFECT OF TRYPTOPHAN DEPLETION ON MOOD IN MEDICATION-FREE, FORMERPATIENTS WITH MAJOR AFFECTIVE-DISORDER

Acute tryptophan depletion (ATD) induces transient clinical relapse in medicated patients with major affective disorder. Our objective was t o determine whether this effect persists once patients are euthymic an d off antidepressants. Thus, we examined the effects ATD in fully remi tted, medication-free, former patients with major depression (n = 14). ATD had no significant effect on mood. These results suggest that the previous report that ATD substantially lowers mood in pharmacological ly treated patients reflects a reversal of mechanisms involved in the therapeutic effects of antidepressants. Alternatively, ATD might induc e clinical relapse only in subgroups that have yet to be identified. ( C) 1997 American College of Neuropsychopharmacology