Longitudinal Patterns of Compliance in Drug Treatment Courts: A Group-based Trajectory Modeling Approach

Drug treatment courts (DTCs) rely on structured supervision and treatment to curb substance use among justice-involved individuals. Using group-based trajectory modeling, this study identifies early-phase patterns of in-program substance use among 320 adult DTC participants, measured through positive drug tests across the first 90 days. Three distinct trajectories emerged: abstainers, responders, and non-responders. Logistic regression analyses revealed that abstainers had significantly higher odds of program graduation compared to non-responders. In contrast, responders—despite reductions in substance use—did not have higher odds of completion, suggesting that early behavioral improvement alone may be insufficient for successful program outcomes. These findings highlight early compliance monitoring as an indicator of treatment responsiveness that can inform more efficient, individualized interventions tailored to participants.