Abstinence and retention outcomes in a smoking cessation program among individuals with co-morbid substance use and mental disorders.

Tobacco use is the leading cause of preventable death in the world. Although cigarette smoking prevalence has decreased, there are still disparities in morbidity and mortality experienced by individuals with substance use and/or mental disorders when compared to general population. The aim of this study was to compare treatment outcomes between three subgroups of smokers: individuals with substance use disorder (SUD-only), individuals with mental disorder without substance use disorders (MD-only), and individuals with co-morbid substance use and mental disorder (SUD + MD). Data of 498 smokers enrolled in a 6-week smoking cessation program in Brazil were analyzed. Sociodemographic, medical and tobacco use information were collected at baseline. Treatment included group cognitive behavioral therapy (CBT) and pharmacotherapy. The primary outcome was defined as "self-report 4-week quitter" (SR4WQ), a standardized measure to assess treatment success. Retention to treatment was also investigated. Associations between groups were analyzed using unadjusted and adjusted logistic regression models. The results showed that SUD + MD had worse outcomes when compared to the other two groups. After adjusting for level of smoking dependence and the use of medication, abstinence and retention to treatment of SUD-only became equivalent to SUD + MD. Because tobacco and other substance addictions share similar mechanisms, having history of SUD might impair successful results of conventional smoking programs. There is a need to further investigate specific variables associated with treatment success for a more resistant subgroup of individuals in mental health and perhaps to invest in more intensive actions, such as the use of combined pharmacotherapy and adapted CBT approaches.