Umbrella review of systematic reviews of peer support in substance use settings

Purpose The purpose of this umbrella review is to synthesise existing evidence on the effectiveness and implementation of peer support in substance use settings, providing insights into its benefits, challenges and implications for practice and research. Design/methodology/approach The preferred reporting items for systematic reviews and meta-analyses were used to guide an umbrella review. Three databases were searched: Academic Search Complete, Scopus and the Web of Science, supplemented with bibliography searches. Articles were included if they were peer reviewed in the English language from inception to 2024 and reported on peer support in substance use contexts. The Joanne Briggs Institute Critical Appraisal Checklist for Systematic Reviews and Research Syntheses was used to assess the quality of the included reviews. Findings are reported using a narrative synthesis. Findings The search yielded 4,062 articles, of which 8 systematic reviews were included, encompassing 177 (N = 177) primary studies with a combined sample size of 38,659 (N = 38,659) participants. Peer support in substance use settings was linked to improved outcomes, including reduced substance use severity, enhanced treatment engagement and better social supports. Challenges identified included inconsistent training, role definitions and organisational barriers, such as stigmatising attitudes and limited structural support. Most reviews used a narrative synthesis to report results, with no meta-analyses. Critical appraisal categorised the reviews as 25% high quality, 25% moderate quality, 25% low quality and 25% critically low quality. The findings further highlighted the need for clearer implementation strategies, standardised training and recovery-oriented care models to optimise peer support effectiveness. In addition, the role of the randomised control trial as a method for evaluating peer support is considered. Originality/value This umbrella review uniquely synthesises evidence from diverse systematic reviews on peer support in substance use settings, highlighting the multidimensional benefits and challenges while addressing critical gaps in implementation strategies and methodological approaches. It offers a novel perspective on optimising peer roles within recovery-oriented care models.