title: Mood effects of 24-hour tryptophan depletion in healthy first-degree relatives of patients with affective disorders.
abstract: 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.
authors.affiliation: Department of Psychiatry and Neuropsychology, Maastricht University, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Klaassen
authors.forename: W J
authors.initials: WJ
authors.lastname: Riedel
authors.forename: A
authors.initials: A
authors.lastname: van Someren
authors.forename: N E
authors.initials: NE
authors.lastname: Deutz
authors.forename: A
authors.initials: A
authors.lastname: Honig
authors.forename: H M
authors.initials: HM
authors.lastname: van Praag
mesh_terms: D000293:Adolescent; D018592:Cross-Over Studies; D003863:Depression / Q000097:blood / Q000235:genetics; D004311:Double-Blind Method; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000097:blood* / Q000235:genetics*; D011569:Psychiatric Status Rating Scales; D012016:Reference Values; D012727:Sex Characteristics; D014364:Tryptophan / Q000008:administration & dosage / Q000172:deficiency*
chemical_list: D014364:Tryptophan