Protocol of a randomized controlled trial examining psychosocial enhancement and standard medication treatment for co-occurring opioid use and mental health disorders: A half fractional factorial randomized controlled trial.

Background: The opioid epidemic disproportionately affects individuals with co-occurring opioid use and mental health disorders (COD), who often have poor treatment engagement. Multicomponent treatment models are popular solutions to increase treatment access and engagement for those with COD. Maintaining Independence and Sobriety through Systems Integration, Outreach and Networking (MISSION) is a hybrid multicomponent linkage and treatment approach that provides assertive community outreach combined with psychosocial treatment. This protocol paper describes a randomized controlled trial comparing MISSION and medication for opioid use disorder (MOUD), its multicomponent parts along with MOUD, and MOUD treatment as usual (TAU) to assess improvements in health and social outcomes.

Methods: This study will use a half fractional factorial design and randomize 1000 patients with COD to one of five treatment conditions: (1) the full MISSION intervention plus MOUD; (2-4) a combination of two out of three MISSION components plus MOUD; or (5) TAU. Secondary aims include examination of mechanisms of action, economic evaluation of the implementation of MISSION and/or its components plus MOUD versus TAU, and exploratory predictive modeling to match optimal MISSION parts with patient needs.

Discussion: This randomized controlled trial will help determine the effectiveness of MISSION (or its parts) and MOUD compared to TAU to improve engagement in treatment, substance use, and mental health symptoms. This trial is the first to compare MISSION and its parts with MOUD versus TAU in a real-world treatment scenario to determine which components are necessary and sufficient to drive treatment outcomes according to patient needs.