Mood effects of 24-hour tryptophan depletion in healthy first-degree relatives of patients with affective disorders. Academic Article uri icon


  • BACKGROUND: Acute tryptophan (TRP) depletion was evaluated in healthy volunteers with or without a family history of major affective disorder (FH+ versus FH-). METHODS: Twenty-seven subjects (16 FH+, 11 FH-) received 100 g of an amino acid mixture with and without TRP according to a placebo-controlled, double-blind cross-over design and a diet devoid of TRP for the next 24 hours. RESULTS: The ratio TRP/large neutral amino acids declined to 22% of baseline values after 6 hours, and increased during the night reaching 85% of baseline after 24 hours. Overall, after 6 hours, TRP depletion lead to a lowering of mood, but after 24 hours, these changes were no longer detected. Mood changes and gastrointestinal side effects were significantly more evident in FH+ subjects than in FH- subjects. CONCLUSIONS: Our data support the hypothesis that subjects with a positive family history for depression are predisposed to increased vulnerability to the adverse consequences of serotonergic imbalance.

published proceedings

  • Biol Psychiatry

author list (cited authors)

  • Klaassen, T., Riedel, W. J., van Someren, A., Deutz, N. E., Honig, A., & van Praag, H. M.

citation count

  • 118

complete list of authors

  • Klaassen, T||Riedel, WJ||van Someren, A||Deutz, NE||Honig, A||van Praag, HM

publication date

  • August 1999