Law and Human Behavior, Vol 50(3), Jun 2026, 261-277; doi:10.1037/lhb0000655
Objective: Persons with behavioral disorders, including those with dual disorders (DDs; i.e., co-occurring mental and substance use disorders [SUDs]), are overrepresented in the criminal justice system. Mental health courts (MHCs) offer an alternative to incarceration and aim to reduce recidivism. However, research indicates that participants with a SUD often complete MHCs at lower rates than those without, highlighting the need to identify effective services that support completion and improve outcomes for this group. This study examines how MHCs support participants with DDs. Hypotheses: We hypothesized that MHCs will use SUD-specific intervention objectives (e.g., SUD services and treatment objectives) to guide participants with DDs through the MHC process, positively influencing MHC completion. Method: Using a sample of 877 participants (261 with a SUD) from 10 MHCs in Quebec, Canada, we conducted bivariate analyses comparing psycho-socio-criminological profiles and MHC interventions for participants with and without a SUD. Decision-tree analysis assessed 16 individual characteristics and events (e.g., factors beyond the MHC team’s control during program participation) as well as 19 intervention objectives (e.g., types of services, treatment objectives, and conditions set by multidisciplinary teams) to identify which factors effectively support participants with a SUD in graduating from MHCs. Results: Bivariate analyses show that MHC teams utilize SUD-specific objectives, conditions, and services to address the many clinical and criminogenic needs of participants with DDs. Decision-tree analysis revealed that participants with DDs benefited the most from medical and psychosocial services to complete the MHC. Conclusions: The fact that medical and psychosocial services help participants with DDs successfully complete MHCs suggests that prioritizing access to these services during the program is essential for improving completion rates. These findings highlight the importance of tailoring MHC interventions to the complex needs of this group, such as medical care, housing, and workforce integration programs. (PsycInfo Database Record (c) 2026 APA, all rights reserved)