Background. More than 50% of rural counties in the US do not have a single buprenorphine-waived provider, and approximately 10% of people in the US live more than 10 miles away from their nearest prescriber. Compounding the devastating effects of the opioid use disorder (OUD) crisis in underserved, rural areas is increasing polysubstance use, notably stimulant use disorder co-occurring with OUD. Since 2019, our team has filled a void of rural addiction treatment practitioners in underserved rural Maryland areas by providing buprenorphine for OUD treatment with the use of telemedicine (TM) aboard a mobile treatment unit (MTU). Our team has demonstrated the effectiveness of the TM-MTU model in reducing opioid use by 32.8% at three- months. Yet, 92% of patients in the past year presented with polysubstance use at intake, approximately half with OUD and stimulant use. Further, treatment retention is a challenge, amplified by polysubstance use; less than 60% of patients were retained at three-months. Reinforcement-based approaches, such as contingency management, have empirical support for improving treatment retention and stimulant use, yet have low adoption in community settings due to organizational and provider barriers, including cost. A behavioral reinforcement-based approach, such as behavioral activation (BA), which aims to increase positive reinforcement through rewarding, substance-free behaviors, may be a promising effective and sustainable strategy to improve both OUD treatment retention and polysubstance use, particularly stimulant use. Further, our team has demonstrated that it is feasible to train peer recovery specialists (PRSs) in BA. Preliminary Studies. This proposal builds upon our team’s prior studies demonstrating the feasibility, acceptability, and effectiveness of: 1) the TM-MTU model reaching rural communities hard hit by the OUD crisis and polysubstance use; 2) integrating PRS support on the TM-MTU; and 3) a PRS-delivered BA intervention (“Peer Activate”) for improving treatment retention and reducing polysubstance use, including OUD and stimulant use. Approach. Building upon this work, we propose a randomized Type 1 hybrid effectiveness-implementation trial (n=180) to evaluate the PRS-delivered BA intervention on the MTU (Peer Activate-MTU) compared to enhanced treatment as usual (ETAU; facilitated referrals and general peer support) on the following over 12- months: (1) effectiveness outcomes: a) OUD treatment retention (primary: chart review of appointment attendance); b) polysubstance use (co-primary: urinalysis of co-occurring use of ≥2 substances); and c) buprenorphine adherence (secondary: urinalysis and pharmacy refill); (2) implementation outcomes, including feasibility, acceptability, fidelity, and adoption guided by RE-AIM; (3) cost of implementing and sustaining Peer Activate-MTU and its economic value relative to ETAU. Implications. This proposal is designed to lead to a potentially scalable model for improving OUD treatment retention and polysubstance use, particularly co- occurring OUD and stimulant use, and increasing the reach of addiction treatment in underserved, rural areas.

Project Narrative There is a disproportionate burden of opioid use disorder and co-occurring polysubstance use, including stimulant use disorder, in underserved, rural areas of the US, yet a lack of resources, contributing to these communities being poorly equipped to meet the increasing need for addiction treatment services. This study aims to evaluate how peer recovery specialists, trained in an evidence-based intervention, behavioral activation, to improve retention in care and polysubstance use could be delivered in a mobile treatment unit alongside telemedicine- prescribed buprenorphine. The aim is to develop a model that could be sustainably delivered to improve health and substance use outcomes in underserved, rural areas.