MOOD RESPONSE TO ACUTE TRYPTOPHAN DEPLETION IN HEALTHY-VOLUNTEERS - SEX-DIFFERENCES AND TEMPORAL STABILITY

We investigated (I) the mood response of normal women, without a famil y history of major affective disorder to acute tryptophan depletion, a nd (2) the temporal stability of the mood change, within subjects, whe n rechallenged at least I month later. To deplete tryptophan, a trypto phan deficient amino acid mixture was ingested. The control treatment was a nutritionally balanced amino acid mixture containing tryptophan. A marked lowering of plasma tryptophan (80% to 90%) was achieved by b oth depletions. Compared to the balanced condition, the women exhibite d a significant lowering of mood after the first tryptophan depletion on the elation-depression (p<.05), energetic-tired (p<.005), confident -unsure (p<.02), and clearheaded-confused (p<.01) scales of the bipola r profile of mood slates. Whereas a lowering of mood was not found in a comparable sample of males studied earlier, these results were simil ar to those obtained in healthy males at genetic risk for major affect ive disorder (MAD). Inasmuch as a family history of MAD and female sex are predisposing factors to depression, these results suggest that a mood-lowering response to acute tryptophan depletion may occur prefere ntially in subjects with a susceptibility to lowered mood. However, th e mood response to tryptophan depletion exhibited poor temporal stabil ity in individual subjects. (C) 1996 American College of Neuropsychoph armacology