Digitally delivered cognitive bias modification for interpretation targeting hostile interpretation bias in compulsory drug rehabilitation: A feasibility randomized trial.

BACKGROUND: Hostile interpretation bias (HIB) is a cognitive correlate of aggression. Cognitive bias modification for interpretation (CBM-I) has shown mixed effects on HIB and aggressive behavior, but its feasibility among people who use drugs (PWUD) in compulsory rehabilitation settings remains unclear. This feasibility trial evaluated a digitally delivered CBM-I (dCBM-I) program for PWUD and explored whether changes in HIB were associated with aggression change.

METHODS: In this assessor-blinded feasibility randomized controlled trial, 60 PWUD from a compulsory rehabilitation facility were randomized to dCBM-I or a no-treatment control group. The dCBM-I program comprised four 20-minute sessions over two weeks, completed on researcher-provided tablets with on-site support. Outcomes were assessed at baseline, mid-intervention, post-intervention, and one-month follow-up. Linear mixed models tested intervention effects, and exploratory mediation analysis examined whether HIB change was associated with an indirect pathway from intervention condition to aggression change.

RESULTS: The program showed high feasibility and acceptability. A significant group × time interaction was observed for HIB, indicating reduced HIB in the dCBM-I group at post-intervention and one-month follow-up. No significant group × time interactions were observed for aggression or secondary symptom outcomes, including anxiety, depression, anger, and craving. Exploratory mediation analysis showed a significant indirect effect through HIB change; however, this finding should be interpreted as hypothesis-generating.

CONCLUSION: dCBM-I was feasible and acceptable in this supervised institutional setting and showed evidence of proximal target engagement. Definitive conclusions about behavioral efficacy require adequately powered active-controlled trials.