Abstract
We studied the effect of acute tryptophan depletion (ATD), which transiently reduces brain serotonin, on negative symptoms and cigarette smoking topography in schizophrenic smokers. Nicotine-dependent schizophrenics (n = 11) and nonpsychiatric controls (n = 8) were examined after ingesting comparable mixtures that do and do not deplete plasma tryptophan. Tryptophan-depleting and placebo mixtures were administered double-blind and in counterbalanced order. Conditions were separated by a 1-week interval. Psychopathologic symptoms (negative symptoms, depression) and smoking topography (time to first puff, number of puffs per cigarette, puff duration, interpuff interval, cigarette duration, and percentage of cigarette smoked) were measured before ingestion and again beginning 5 h after each mixture, corresponding to the time of maximal tryptophan depletion. Analyses were conducted using repeated measures analyses of variance (psychopathologic symptoms) and analyses of covariance (smoking topography) controlling for cigarette length. We found that ATD influenced smoking topography in both schizophrenics and nonpsychiatric controls in a manner suggestive of increased desire to smoke. Schizophrenics exhibited increased puff duration and decreased cigarette duration. Controls displayed increased puff duration. ATD did not produce changes in negative symptoms or depression. Compromising brain serotonin via ATD appears to intensify smoking behavior in nicotine-dependent individuals directly, rather than indirectly through changes in either mood or psychopathologic symptoms.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 640-648 |
| Number of pages | 9 |
| Journal | Neuropsychopharmacology |
| Volume | 30 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2005 |
Funding
This study was funded by an NRSA Individual Predoctoral Fellowship (F31 DA05854) from the National Institute on Drug Abuse awarded to Brian Hitsman, PhD. Additional research support was provided by a Mentored Clinical Scientist Development Award (K08 DA017145) to Brian Hitsman, PhD, a National Heart Lung and Blood Institute grant (HL59348) and a VA Merit Review award to Bonnie Spring, PhD, an American Cancer Society grant awarded to Regina Pingitore, PhD, and by the National Cancer Institute, Transdisciplinary Tobacco Use Research Center Grant, P50 CA84719. This study was performed in partial fulfillment of the clinical psychology doctoral degree of Brian Hitsman, PhD, under the direction of Bonnie Spring, PhD, while at Finch University of Health Sciences/The Chicago Medical School. We thank Dianna Gunnarsdottir, PhD, Michele Pergadia, PhD, Donna Delaney, Edward Fink, and Elizabeth Rebocho for their assistance with participant screening and testing. An earlier version of this report was presented at the Eighth Annual Meeting of the Society for Research on Nicotine and Tobacco, Savannah, GA, February 2002.
Keywords
- Motivation
- Nicotine
- Schizophrenia
- Serotonin
- Smoking
- Tryptophan
ASJC Scopus subject areas
- Psychiatry and Mental health
- Pharmacology
