title: Effects of tryptophan depletion on acute smoking abstinence symptoms and the acute smoking response.
abstract: Given the putative role of serotonin in the modulation of smoking withdrawal and the central actions of nicotine, this study examined the affective and neuroelectric correlates of smoking abstinence and cigarette smoking following depletion of the serotonin precursor, tryptophan. In a randomized, double-blind two session (tryptophan depletion [TD] vs. nondepletion), placebo-controlled design, spectrally analyzed electroencephalogram (EEG), self-ratings of withdrawal symptoms and mood states were assessed in 18 male cigarette smokers before smoking abstinence, 5 h postsmoking abstinence and again following sham smoking and the smoking of one cigarette. Compared to a nutritionally balanced amino acid (AA) mixture containing tryptophan (i.e., placebo mixture), oral ingestion of a similar mixture devoid of tryptophan resulted in a 70% reduction of plasma tryptophan but failed to alter the appearance or reversal (by acute cigarette smoking) of withdrawal symptoms, negative mood states and increased slow wave EEG in male smokers deprived of cigarettes. These results, although not supporting a role for the serotonergic system in acute smoking and early smoking abstinence symptoms, are discussed in relation to the neuropharmacology of smoking behavior and suggestions for future work.
authors.affiliation: Department of Psychology, Rehabilitation Centre, Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: Mary
authors.initials: M
authors.lastname: Perugini
authors.forename: Colleen
authors.initials: C
authors.lastname: Mahoney
authors.forename: Vadim
authors.initials: V
authors.lastname: Ilivitsky
authors.forename: Simon N
authors.initials: SN
authors.lastname: Young
authors.forename: Verner
authors.initials: V
authors.lastname: Knott
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology*; D000704:Analysis of Variance; D004311:Double-Blind Method; D004569:Electroencephalography / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D012907:Smoking / Q000097:blood* / Q000523:psychology; D016540:Smoking Cessation / Q000523:psychology; D013375:Substance Withdrawal Syndrome / Q000097:blood* / Q000523:psychology; D014364:Tryptophan / Q000097:blood / Q000378:metabolism*
chemical_list: D014364:Tryptophan