Drug use and crime seem inextricably linked. Law enforcement responses to drug use tend to funnel people who use drugs into the criminal justice system rather than treatment, and those drug users who are imprisoned often have multiple, co-occurring mental health problems and/or suffer from infectious diseases including HIV, hepatitis C, and tuberculosis. Prisons provide a rare but regrettable opportunity to identify and respond to these needs, but correctional policies with respect to drug use and related harms often diverge from the evidence. Where such responses are evidence-based, they are rarely delivered at scale. Drug use in prison remains common and, in the absence of evidence-based harm reduction measures, is high risk. Relapse to drug use after release from prison is normative, such that incarceration can at best be conceived of as an interruption in drug use. People released from prison are at markedly increased risk of drug-related harms including fatal drug overdose and preventable hospitalisation, and are at increased risk of reincarceration. Greater investment in independent, rigorous research on the epidemiology of substance use and related harms in people who cycle through prisons, and a renewed commitment to aligning correctional policy and practice with the evidence, will have measurable benefits for public health, public safety, and the public purse.
