Acute psychomotor, subjective and physiological responses to smoking in depressed outpatient smokers and matched controls

Rationale: Cigarette smoking is highly prevalent in people diagnosed with depression, and depressed smokers are less likely to quit. Examining depressed smokers' responses to smoking will help determine the role of depression in maintaining cigarette smoking. Objectives: To determine the psychomotor, subjective and physiological effects of cigarette smoking in currently depressed smokers versus matched controls. Materials and methods: Fourteen currently depressed smokers and 14 never-depressed smokers, matched in age, gender, nicotine dependence and daily cigarette consumption, smoked three cigarettes at half-hourly intervals. All smokers were non-deprived. Self-reported mood and craving for cigarettes, performance on a simple reaction time task, expired-air carbon monoxide, heart rate and blood pressure were assessed before and after smoking each cigarette. Smoking topography was also assessed. Results: Depressives and controls did not differ in terms of dependence on cigarettes or expired-air carbon monoxide. Topographic and cardiovascular measures were similar in depressed and control participants, suggesting that they smoke cigarettes in a similar manner. However, depressives displayed enhanced reaction time performance after the first cigarette. Positively reinforced craving was reduced after smoking each cigarette but returned to baseline levels within 30 min in depressed but not in control smokers. Depressed smokers also displayed higher levels of negatively reinforced craving. Both depressives and controls reported improved positive mood after smoking. Conclusions: Cigarette smoking in non-deprived depressed smokers enhances psychomotor performance and the reduction of positively reinforced craving in depressed smokers after smoking is transient, suggesting that enhanced craving may play a role in the maintenance of smoking in depression.