Depression vulnerability moderates the effects of cognitive behavior therapy in a randomized controlled trial for smoking cessation

Several clinical trials have tested the hypothesis that smoking cessation treatments with a mood management component derived from cognitive behavior therapy (CBT) for depression would be specifically effective for depression-vulnerable smokers, with mixed results. This trial addressed methodological concerns with some of the previous studies to clarify whether depression vulnerability does in fact moderate CBT smoking cessation outcome. The study compared 8-session group CBT with a time-matched comparison group condition in a sample of 100 cigarette smokers randomized to treatment condition. Each treatment group was led by one of 7 American University clinical psychology graduate students; therapists were crossed with treatment conditions. Outcome (7-day point prevalence abstinence) was evaluated 1 month and 3 months after quit date. Baseline self-reported depression vulnerability (sample median split on the Depression Proneness Inventory) moderated treatment response, such that more depression-prone smokers fared better in CBT whereas less depression-prone smokers fared better in the comparison condition. These results may have implications for determining when to use CBT components in smoking cessation programs.