Abstract
Background: People with co-occurring substance use and mental health disorders who experience chronic homelessness often have difficulty engaging in both treatment and support services. Maintaining Independence and Sobriety through Systems Integration, Outreach and Networking (MISSION) is a multicomponent wraparound integrated co-occurring substance use and mental health disorders treatment and linkage intervention comprised of three evidence-based components (Critical Time Intervention case management and peer support, Dual Recovery Therapy, and Peer Support). Although prior MISSION studies have demonstrated positive outcomes for this population, and fidelity (i.e., fidelity to the model) has predicted improvements in criminal legal outcomes, the present study builds on these findings by examining to what extent fidelity to the MISSION model improves behavioral health and housing outcomes.
Methods: Individuals with co-occurring substance use and mental health disorders experiencing chronic homelessness (N = 108) completed a comprehensive intake and were offered up to 12-months of MISSION treatment and services. Services received and fidelity to the MISSION model were tracked weekly. Generalized linear mixed models were used to examine whether fidelity to the overall MISSION model and to each component predicted improvements in behavioral health, substance use, and housing stability outcomes.
Results: Among the sample, 70.3% were male, 78.8% were non-Hispanic, 72.3% were White, and were homeless for 8.3 years on average. Fidelity to the overall MISSION model ranged from 0.0 to 296.0%. Generalized linear mixed models demonstrated mixed relationships between fidelity to the MISSION model (and each component) including improvements in behavioral health, reduced overall illicit substance use and alcohol use in the past 6-months, and improvements in housing stability.
Conclusions: This study demonstrated that fidelity to the MISSION model had a direct impact on improving outcomes for individuals with co-occurring substance use and mental health disorders who have experienced chronic homelessness. These findings have important implications for settings that implement MISSION or other multicomponent interventions as fidelity to the model will yield greater behavioral health, substance use, and housing stability improvements.