BACKGROUND

Although depression and smoking commonly co-occur, the mechanisms underpinning this association are poorly understood. One hypothesis is that depression promotes tobacco dependence, persistence and relapse by increasing sensitivity to acute negative mood and abstinence induced tobacco-seeking behavior.

METHODS

Twenty nine daily smokers of >10 cigarettes per day, nine with major depression and 20 without, completed two laboratory sessions one week apart, smoking as normal prior to session 1 (sated session), and 6h abstinent prior to session 2 (abstinent session). In both sessions, tobacco-seeking was measured at baseline by preference to view smoking versus food images. Negative mood was then induced by negative ruminative statements and sad music, before tobacco-seeking was measured again at test.

RESULTS

In the sated session, negative mood induction produced a greater increase in tobacco choice from baseline to test in depressed (p<0.001, η=0.782) compared to non-depressed smokers (p=0.045, η=0.216, interaction: p=0.046, η=0.150). Abstinence also produced a greater increase in baseline tobacco choice between the sated and abstinent sessions in depressed (p=0.002, η=0.771) compared to non-depressed smokers (p=0.22, η=0.089, interaction: p=0.023, η=0.189). These mood and abstinence induced increases in tobacco choice were positively associated with depression symptoms across the sample as a whole (ps≤0.04, η≥0.159), and correlated with each other (r=0.67, p<0.001).

CONCLUSIONS

Current major depression or depression symptoms may promote tobacco dependence, persistence and relapse by increasing sensitivity to both acute negative mood and abstinence induced tobacco-seeking behavior. Treatments should seek to break the association between adverse states and smoking to cope.