Purpose of Review: Evaluate literature examining whether mutual help groups (MHGs) for illicit drug use disorders benefit participants.

Recent Findings: Recent studies consistently show that MHG attendance and involvement predict reductions in drug use and addiction severity. More rigorous methodologies offer stronger evidence of effectiveness, but additional controlled trials are needed. Drug-focused MHG challenges include lower success rates of professionally-delivered interventions to facilitate participation compared to alcohol-focused MHGs, and stigma towards opioid agonist medications. Culturally-tailored MHG formats may benefit specific populations (e.g., racial/ethnic minorities). Non-12 step MHGs like SMART Recovery show promise, but research is limited. Online delivery formats positively affect retention.

Summary: Evidence on the benefits of MHGs for drug use disorders is encouraging but incomplete. MHG engagement may be enhanced by cultural adaptations and reduced stigma towards medications. Future research should focus on non-12 step MHGs, treatment integration, optimizing online formats, and understudied groups (e.g., Indigenous populations). Selection bias remains a challenge in evaluations of MHG effectiveness.