This Campbell policy brief summarises findings from 12 systematic reviews on interventions to reduce substance abuse.

Close to 300 million people around the world use illegal substances, and over 35 million suffer from drug use disorders (UNODC, World Drug Report 2019). Substance abuse has dramatic adverse consequences for individuals, their families and society at large. Victims of substance abuse are often unable to maintain employment or stable housing and may engage in crime and prostitution. Mental and other health issues are closely associated with substance abuse. Almost 11 million people inject drugs, of whom 1.3 million are living with HIV, 5.5 million with Hepatitis C, and 1 million with both HIV and Hepatitis C (WHO, Substance Abuse Facts and Figures).