Time-varying smoking abstinence predicts lower depressive symptoms following smoking cessation treatment.

INTRODUCTION The question of whether abstinence during the months following a planned quit attempt exacerbates or improves depressive symptoms is an important clinical issue. Extant research has primarily modeled between-person covariation between postquit abstinence and depressive symptom trajectories. However, this approach cannot account for potential third variables between participants that may affect both smoking and depression. Accordingly, the current study examined within-person covariation between time-varying abstinence and depressive symptom in a multilevel model (MLM), which allowed for transitions between smoking statuses within a participant. METHODS Participants were 236 heavy drinking smokers in a randomized clinical trial testing the efficacy of incorporating brief alcohol intervention into smoking cessation treatment. Depressive symptoms and biochemically verified abstinence were assessed 1 week prior to and 2, 8, 16, and 26 weeks after quit date. RESULTS MLMs indicated a slight increase in depressive symptoms over time in the sample as a whole. However, there was an inverse relation between time-varying abstinence (vs. smoking) and concurrent level of depressive symptoms, indicating that transitions from smoking to abstinence within individuals were associated with reductions in depressive symptoms. CONCLUSIONS During the first 6 months following a planned quit attempt, being abstinent in a particular week appears to be associated with lower levels of concurrent depressive symptoms. These results are not concordant with the view that intentional smoking abstinence exacerbates depressive symptoms. Efforts to promote smoking cessation should highlight that individuals are likely to feel more rather than less psychologically healthy when they successfully quit smoking.