Sarcouncil Journal of Internal Medicine and Public Health

Abstract: Background: Individuals with co-occurring mental health and substance use disorders face elevated morbidity, fragmented care pathways, and disproportionate utilization of healthcare services in the United States. Multidisciplinary care-coordination models have been extensively advocated as a solution to these challenges; however, their effectiveness has been documented with considerable variability. Objective:To systematically synthesize recent U.S.-based evidence evaluating the effectiveness of multidisciplinary care-coordination models for individuals with co-occurring mental health and substance use disorders. Methods: A PRISMA-compliant systematic review was conducted using peer-reviewed, rigorously documented studies published from 2020 onward. Multiple databases were searched to identify studies evaluating multidisciplinary or integrated care-coordination models. Due to heterogeneity in study designs, interventions, and outcome measures, findings were synthesized using a narrative approach Findings: Across 30 studies, multidisciplinary care-coordination models improved care continuity, treatment engagement, and selected utilization outcomes relative to fragmented care. Evidence of direct clinical benefit was mixed and varied by model and implementation context. Workforce, data integration, and reimbursement barriers continued to constrain scalability and sustainability. Conclusion: Multidisciplinary care coordination represents a critical strategy for improving service delivery for individuals with co-occurring disorders; however, its effectiveness is contingent on implementation quality and supportive policy environments. More rigorous comparative and equity-focused research is needed to inform durable system-level change.