Three decades of research in substance use disorder treatment for syringe services program participants: a scoping review of the literature.

SSPs can successfully refer participants to SUD treatment and deliver onsite buprenorphine treatment. Future studies should explore strategies to optimize the implementation of onsite buprenorphine. Because linkage rates were suboptimal for methadone, offering onsite methadone treatment at SSPs may be an appealing solution, but would require changes in federal regulations. In tandem with continuing to develop onsite treatment capacity, funding should support evidence-based linkage interventions and increasing accessibility, availability, affordability and acceptability of SUD treatment programs.