title: Effects of L-tryptophan on daytime arousal.
abstract: A double-blind placebo-controlled study was carried out on 20 subjects to examine the early morning sedative effects of 2 g of L-tryptophan. Using brain mapping technique, 16-channel EEG recordings were topographically displayed. A distinct increase in theta amplitude, predominantly in the central region, together with an alpha reduction was observed after L-tryptophan administration, signs characterizing the EEG of drowsiness. Subjective self-rated sleepiness increased after the ingestion of L-tryptophan. Psychomotor performance, assessed by means of various psychometric tests, was not affected by this low dose of L-tryptophan.
authors.affiliation: Department of Psychiatry, National University Hospital, Reykjavik, Iceland.
authors.forename: B
authors.initials: B
authors.lastname: Thorleifsdóttir
authors.forename: J K
authors.initials: JK
authors.lastname: Björnsson
authors.forename: M
authors.initials: M
authors.lastname: Kjeld
authors.forename: H
authors.initials: H
authors.lastname: Kristbjarnarson
mesh_terms: D000328:Adult; D001143:Arousal / Q000187:drug effects*; D001931:Brain Mapping; D002940:Circadian Rhythm / Q000187:drug effects*; D004311:Double-Blind Method; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance; D012701:Serotonin / Q000096:biosynthesis; D012894:Sleep Stages / Q000187:drug effects; D014364:Tryptophan / Q000494:pharmacology*
chemical_list: D012701:Serotonin; D014364:Tryptophan