The Effects of High-Dose and Low-Dose Tryptophan Depletion on Mood and Cognitive Functions of Remitted Depressed Patients.

L. Booij, A.J.W. van der Does*, P.M.J. Haffmans, W.J. Riedel, D. Fekkes, M.J.B. Blom

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

28 Downloads (Pure)


It has frequently been demonstrated that acute tryptophan depletion (ATD) induces a transient depressed mood in some patients who are in remission from depression. However, the effects of ATD on cognitive processes in remitted depressed patients have not been investigated. The aim of the present study was to investigate the effects of different extents of depletion on mood and cognitive tasks involving neutral and emotional stimuli. Twenty patients in remission or in partial remission from depression received ATD in a double-blind, crossover design. Mood was assessed at both sessions before, at +6.5 h and +24 h afterdepletion. Cognitive assessment in both sessions started at +4.75 h, and also before and after the whole procedure. The ATD mixtures induced the expected reductions of plasma tryptophan levels. High-dose ATD induced a depressive response in a subsample of patients and impaired theprocessing of positive information independent of mood change. Attention for neutral stimuli (Stroop interference) improved in a dose-dependent manner. ATD may affect mood and cognition via different pathways: one implicated in mood regulation and the processing of emotional information, and one for the processing of neutral information. The first pathway may be more important for discriminating vulnerability to impaired serotonin function. The comparison of the effects of high-dose and low-dose ATD is useful for those studies aiming to investigate the relationships among 5-HT, mood and cognition.
Original languageEnglish
Pages (from-to)267-275
JournalJournal of Psychopharmacology
Issue number3
Publication statusPublished - 1 Jan 2005

Cite this