Do posttreatment increases in social recovery capital mediate the relationship between lower internalizing symptoms...

Substance use disorders frequently co-occur with internalizing disorders, such as depression and anxiety, particularly among emerging adults in treatment. While a growing literature has examined bidirectional associations between internalizing symptoms and substance use, findings remain mixed. The present study investigated whether social recovery capital (SRC) mediated bidirectional internalizing symptoms and substance use behaviors associations.

Emerging adults (N = 302, 74% male sex assigned at birth, 95% White) were recruited from a residential substance use treatment facility and assessed at treatment baseline, 1-, 3-, 6-, and 12-month follow-ups (71% retention rate at the 12-month follow-up). Latent growth curve models with structured residuals, which disaggregate between- (i.e., growth processes) and within-person effects (i.e., cross-sectional and lagged associations), examined reciprocal associations between internalizing symptoms, SRC, and substance use outcomes.

Results indicated that SRC and percent days abstinent increased over time, while internalizing symptoms decreased. Substance use consequences initially decreased but increased after the 3-month follow-up. At the within-person level, there was no support for the central hypothesis that SRC would mediate internalizing symptom-substance use associations. Greater internalizing symptoms were contemporaneously associated with higher substance use consequences. More SRC was contemporaneously associated with higher percent days abstinent and lower internalizing symptoms.

Contemporaneous associations between more SRC and lower internalizing symptoms and greater percent days abstinent suggest SRC may facilitate reductions of co-occurring substance use and internalizing symptoms. Future studies should explore alternative timescales and use more comprehensive measures of SRC. (PsycInfo Database Record (c) 2026 APA, all rights reserved).