The shape of change: Determining when mechanisms of behavior change are active in cognitive behavioral treatment for alcohol use disorder using time-varying effect modeling (tvem)

Objective: Research has identified several potential mechanisms of behavior change (MOBCs) in cognitive–behavioral therapy for alcohol use disorder, including alcohol abstinence self-efficacy (AASE), negative affect (NA), and positive affect (PA). However, little is known about when MOBCs affect clinical outcomes during alcohol use disorder treatment. Such information could advance MOBC research by identifying relationships between specific treatment content and varia-tions in MOBCs. This study examined three MOBCs simultaneously to determine their timing and relative influence on percent days abstinent (PDA) and drinks per day (DPD). Method: Data were derived from a parent study assessing pretreatment change in drinking. Participants (n = 205) received 12 sessions of cognitive–behavioral therapy for alcohol use disorder. AASE, NA, and PA were measured at each treatment session, and time-varying effect models (TVEM) were used to examine their association with PDA and DPD. Results: All three MOBCs were associated with PDA and DPD but varied with regard to time course, strength, and direction. For PDA, AASE was positively associated throughout treatment, NA was negatively associated from Sessions 1 to 10, and PA was positively associated from Sessions 1 to 3 and 11 to 12. For DPD, AASE was positively associated from Session 5 to the end of treatment, NA was positively associated throughout treatment although the strength of the association varied and was strongest at the beginning of treatment, and PA was positively associated from Sessions 5 to 12. Conclusions: Results show that MOBCs exert their effects at different times during treatment. In addition to replicating these results, future research should attempt to manipulate MOBCs directly and examine their influence on alcohol outcomes. (J. Stud. Alcohol Drugs, 82, 629–637, 2021).