The moderating influence of nicotine and smoking on resting-state mood and EEG changes in remitted depressed patients during tryptophan depletion.
Comorbidity between depression and tobacco use may reflect self-medication of serotonergically mediated mood dysregulation, which has been associated with aberrant cortical activation and hemispheric asymmetry in patients with major depressive disorders (MDD). This randomized, double-blind study in 28 remitted MDD patients examined the moderating effects of acute nicotine and smoker vs. nonsmoker status on mood and EEG changes accompanying transient reductions in serotonin induced by acute tryptophan depletion (ATD). In smokers, who exhibited greater posterior high alpha power and increased left frontal low alpha power (signs of deactivation) compared to nonsmokers, ATD increased self-ratings of depressed mood and elevated left frontal and right parietal high alpha power (i.e. further cortical deactivation). Smokers were not affected by nicotine administration. In nonsmokers, ATD did not influence depression ratings, but it reduced vigor ratings and increased frontal and posterior theta power; both of which were blocked by acute nicotine. These findings indicate a role for nicotinic receptors in disordered mood.
University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; Department of Psychology, University of Ottawa, Ottawa, ON, Canada; Department of Psychology, Carleton University, Ottawa, ON, Canada; Institute of Cognitive Science, Carleton University, Ottawa, ON, Canada; Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada. Electronic address: Verner.Knott@theroyal.ca.
Verner
V
Knott
Jean-Claude
JC
Bisserbe
Dhrasti
D
Shah
Andrea
A
Thompson
Hayley
H
Bowers
Crystal
C
Blais
Vadim
V
Ilivitsky
D000328:Adult; D000339:Affect / Q000187:drug effects* / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D003865:Major Depressive Disorder / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology*; D004311:Double-Blind Method; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D012701:Serotonin / Q000378:metabolism; D012907:Smoking / Q000503:physiopathology / Q000523:psychology*; D014364:Tryptophan / Q000378:metabolism*
D012701:Serotonin; D009538:Nicotine; D014364:Tryptophan
Depression; Electroencephalography; Mood; Nicotine; Nicotine receptors; Serotonin; Smoking; Tryptophan depletion