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.