The objective of this environmental scan is to summarize evidence on the health and social impacts of decriminalization policies. This document will also describe local, provincial/state, national or international examples of decriminalization policies. The regulation of controlled substances can take formal (i.e., policy or legal change) or informal approaches (i.e., non-enforcement practices), and occurs across a continuum of categories from criminalization to decriminalization to legalization. This scan will include a range of models ranging from formal, national legislation change to local decisions to not enforce personal possession sanctions within a spectrum of decriminalization approaches. Evidence on formal policy to non-legislative decriminalization models will include police diversion, drug treatment courts, formal warning systems, administrative sanctions, and personal use and possession.1 While personal use and possession of drugs is an offense in several of these models, this scan includes approaches that provide alternatives to incarceration. Approaches to legalization (i.e., removal of criminal sanctions and use of regulatory controls) will be briefly summarized in the context of cannabis legalization. Given the legalized status of cannabis in Canada, this scan focuses largely on decriminalization options for other drugs.

Key findings:

• Research has demonstrated significant health, social, and economic harms resulting from laws that criminalize people who use drugs, and in particular Black, Indigenous and racialized communities. To reduce harms, countries, states/provinces and municipalities in Europe, Central Asia, South America, North America and Australia have implemented approaches to decriminalize the personal use and possession of drugs, and in some cases cultivation and noncommercial, community-driven distribution. Most jurisdictions have decriminalized drugs through formal legislation change, while fewer have adopted de facto approaches (i.e., nonenforcement or diversion programs). 
• The published literature on the effectiveness on decriminalization or legalization primarily focuses on cannabis in the American context, while evidence on the decriminalization of the personal use and possession of other drugs was more limited. Economic savings, as well as modest reductions in opioid prescribing may occur following decriminalization of cannabis use. There have also been reported increases of cannabis-related emergency department visits, detectable THC levels in drivers and calls to poison call centres (exposure); several of these records were of lower quality.
• Evidence from Portugal and elsewhere have reported reductions in drug-related harms (e.g., drug-related mortality, HIV and hepatitis C transmission) and costs following the decriminalization of personal use and possession of drugs. There is inconsistent evidence on the effect of decriminalization on drug use patterns.
• Several factors can influence the effectiveness of decriminalization approaches including the pre-existing context and implementation. Along with the need for high quality scientific evidence, more equitable engagement with people who use drugs is needed in the design, development, and evaluation of decriminalization policies as well as parallel planning for health and social justice.
• There are growing calls for the decriminalization of drugs for personal use and possession in Canada, the United States, and Europe. Vancouver became the first Canadian city to formally request an exemption from the Controlled Drugs and Substances Act Section 56(1) in May 2021, and the City of Toronto’s Board of Health submitted a request in early 2022. Implementation and evaluation of proposed decriminalization models can further support understanding of implementation and effectiveness to inform evidence-based drug policy in Ontario.