Substance use negatively impacts change in reinforcement during the year following substance use treatment.

Objective: Although research supports an association between increased alternative reinforcement and decreased substance use, the impact of substance use on changes in reinforcement during posttreatment recovery remains untested. This study tested the effect of abstinence duration and substance use frequency on the trajectories of four reinforcement mechanisms, behavioral activation, reward probability, reward barriers, and valued living, from pre- to 12-month posttreatment.

Method: Adults in intensive outpatient substance use disorder treatment (N = 206) completed self-report measures of the four reinforcement constructs and substance use over six timepoints from pre- to 12-month posttreatment. Latent curve models were used to test the association between reinforcement trajectories and abstinence duration and substance use frequency, respectively.

Results: Lower substance use frequency was associated with significantly improved behavioral activation, reward probability, and reward barriers across the posttreatment period (ps < .05). Higher substance use frequency was associated with significantly lower valued living at each timepoint (ps < .05). Longer abstinence duration was significantly associated with higher behavioral activation and valued living, and lower reward barriers at 12-months (ps < .05).

Conclusions: Substance-free reinforcement improves during treatment and is negatively impacted by substance use frequency during posttreatment. Abstinence duration is positively associated with substance-free reinforcement at 12-month posttreatment. These findings support the conceptualization of reinforcement as a malleable treatment target that is negatively impacted by substance use. (PsycInfo Database Record (c) 2025 APA, all rights reserved).