Alteration of frontal EEG asymmetry during tryptophan depletion predicts future depression

John J.B. Allen, Katherine M. McKnight, Francisco A. Moreno, Heath A. Demaree, Pedro L. Delgado

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Background: Tryptophan depletion (TD) reduces brain serotonin and may induce acute depressive symptomatology, especially among those with a history of Major Depression. Depressive response to TD among euthymic patients with a history of depression also predicts future depression. Better prediction might result by assessing a putative endophenotype for depressive risk, frontal electroencephalographic (EEG) asymmetry, in the context of TD. Method: Nine euthymic history-positive participants and nine controls were administered TD. Symptomatic and EEG frontal asymmetry data were collected for 6 h following TD, and clinical status was followed for the next 12 months. Results: The magnitude of TD-induced change in frontal EEG asymmetry significantly predicted the development of depression during the ensuing six to twelve months, and with greater sensitivity than symptomatic response. Limitations: The results are tempered by the small sample size. Conclusions: Despite the limited sample size, these preliminary results suggest that TD-induced changes in frontal EEG asymmetry may provide a more sensitive indicator of risk for imminent depression than symptomatic response to TD.

Original languageEnglish (US)
Pages (from-to)189-195
Number of pages7
JournalJournal of Affective Disorders
Issue number1-2
StatePublished - May 2009


  • Brain asymmetry
  • Depression
  • EEG
  • Mood
  • Risk
  • Serotonin
  • Tryptophan depletion

ASJC Scopus subject areas

  • Clinical Psychology
  • Psychiatry and Mental health


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