The main outcome in this trial is prolonged abstinence at 6-month and 12-month follow-up. Logistic regression will be used to test for a between-group difference in the proportion of patients with self-reported prolonged abstinence from cigarettes at 6 months. A general linear mixed model will be used to estimate changes depressive symptoms between groups. If there is a significant intervention effect on smoking cessation, meditational analysis will be conducted to examine whether changes in self-efficacy, affect, and motivation to quit mediate the impact of the mood management intervention.