Differences in biobehavioral measures of cigarette smoking by depression symptomology.

Introduction: Research that explores the clinical relevance of subclinical depressive symptoms and smoking is primarily focused on smoking cessation. We examine whether depression symptoms vary across an array of biological (carbon monoxide boost), behavioral (FagerströmTest of Nicotine Dependence, cigarettes per day, smoking topography), and psychological smoking-related outcomes (Questionnaire on Smoking Urges, Withdrawal Symptoms Checklist) in non-treatment-seeking smokers.

Methods: Baseline data were pooled from three research trials with identical procedures designed to assess individual smoking behavior using smokers preferred cigarette brands. Depression symptom level (asymptomatic, subsyndromal, syndromal) was defined using established Center for Epidemiological Depression Scale (CES-D) cutpoint criteria. Smokers were instructed to smoke as usual for one-week. At the beginning and end of the baseline period, nicotine dependence, smoking topography, CO boost, desire to smoke, anticipation of positive reinforcement, negative affect, and withdrawal were measured.

Results: Ordinary least squares linear regression models were used to test the association between depression symptom level and outcome measures adjusting for sex and education (N = 355). The results revealed no differences in topography measures, cigarettes per day and FTND. Smoking withdrawal and smoking urges were higher among both individuals with subsyndromal symptoms and syndromal depression symptoms compared to those who were asymptomatic. Individuals with subsyndromal depressive symptoms experienced higher smoke exposure and higher relief from negative affect.

Conclusion: Increased smoke exposure, greater withdrawal symptoms and urges to smoke, and anticipation of negative affect relief among smokers with subsyndromal depression symptoms suggest that depression symptoms need not reach syndromal levels to alter smoking-related outcomes.