Substance Use Prevalence and Patterns in Vulnerable Populations: A Systematic Review and Meta-Analysis

Substance use-particularly non-alcohol drugs-is markedly more prevalent among vulnerable populations than in the general population. Social exclusion, homelessness, and forced migration amplify risk and highlight the need for integrated prevention, harm-reduction, and mental-health strategies tailored to these groups. These findings can inform policy design and targeted interventions in humanitarian and low-resource contexts.