Drug Policy Reform: What Research Shows About Decriminalization and Public Health Approaches

Drug policy in the United States has long been shaped more by political dynamics than by public health evidence. The consequences of four decades of aggressive criminalization, including mass incarceration, disrupted communities, and limited treatment access, have prompted a growing movement to reconsider how law and policy approach drug use and addiction. Research on the effects of alternative approaches, including decriminalization and harm reduction, has informed policy debates in ways that are beginning to shift the landscape. Criminalization of drug possession and use has not produced the deterrent effects that its proponents anticipated. Rates of drug use in the United States are similar to or higher than rates in countries with more permissive drug laws. Research comparing drug use rates across countries with different legal frameworks does not find that criminalization significantly reduces use. Meanwhile, the social costs of criminalization are substantial: arrests, prosecutions, and incarceration disrupt employment, housing, family relationships, and treatment engagement for people with substance use disorders. The racialized enforcement of drug laws has been documented extensively. Studies using administrative data and controlled experiments consistently find that Black and Latino individuals are arrested, prosecuted, and incarcerated at higher rates than white individuals for comparable drug offenses, despite similar rates of drug use across racial groups. This enforcement disparity has produced lasting consequences for affected communities and has contributed to broader public health inequities that researchers continue to study. Portugal's 2001 decriminalization of personal possession of all drugs provides the most studied natural experiment in drug policy reform. Under Portugal's approach, drug possession is treated as a public health matter rather than a criminal one: people found with small quantities of drugs appear before dissuasion committees rather than courts and may be referred to treatment. Drug use rates did not increase after decriminalization and have remained below European averages. HIV transmission rates among people who inject drugs fell dramatically. Treatment admissions increased. Researchers attribute these outcomes to both the decriminalization itself and substantial concurrent investment in treatment and harm reduction services. Oregon's Measure 110, which decriminalized personal possession of small amounts of most drugs in 2020, has attracted significant research attention as the largest-scale experiment in decriminalization within the United States. Implementation has been challenging: funding for treatment and recovery services that was supposed to flow from cannabis tax revenue was slow to materialize, and law enforcement adaptation was uneven. Early research suggests the law changed drug policy practices on the ground less than anticipated. Oregon subsequently recriminalized personal possession, citing implementation failures. Researchers are studying whether the recriminalization produces the outcomes proponents expected. Harm reduction approaches treat drug use as a public health issue and aim to reduce the negative consequences of use rather than requiring abstinence. Needle exchange programs, which provide sterile injection equipment to people who use drugs, have been extensively evaluated and found to reduce HIV and hepatitis C transmission without increasing drug use. These programs also serve as access points for connecting participants to treatment and other health services. The evidence base for needle exchanges is sufficiently strong that they are supported by major public health organizations despite persistent political opposition in some jurisdictions. Naloxone distribution, which involves making the opioid overdose reversal medication available without a prescription and training community members to use it, is an evidence-based harm reduction strategy with a particularly strong evidence base. Studies find that community naloxone programs reduce overdose deaths. Expanding access to naloxone has been a point of policy consensus in the opioid crisis response. Safe consumption sites, also called supervised injection facilities or overdose prevention centers, allow people to use pre-obtained drugs in a supervised setting with medical staff present to respond to overdoses. These facilities exist in dozens of countries including Canada, Australia, and most of Western Europe. Research consistently finds that supervised consumption sites reduce overdose deaths in their communities without increasing drug use or drug-related crime in surrounding areas. The United States has seen the first licensed sites open in New York City, and early data is being collected. Medication-assisted treatment for opioid use disorder, including buprenorphine and methadone, is among the best-supported interventions in addiction medicine. These medications reduce cravings, prevent withdrawal, and dramatically reduce overdose mortality. Policies that restrict access to medication-assisted treatment, including rules requiring frequent clinic visits or limiting prescribing to specialized facilities, have been shown to reduce treatment engagement. Expanding telemedicine prescribing of buprenorphine, which occurred during the COVID-19 pandemic, has been associated with increased treatment uptake. The research evidence supports a public health approach to drug policy that emphasizes treatment access, harm reduction, and decriminalization of personal use over criminal enforcement. Making this case to policymakers and publics that have been shaped by decades of criminalization rhetoric remains a significant challenge, but the accumulating evidence base provides a foundation for evidence-informed reform.