Distinguishing personal use of drugs from drug supply: Approaches and challenges

The ability to fairly and justly distinguish between drug possession for personal use and drug possession for supply is a central feature of drug laws across the globe. Whether such distinctions pertain to decriminalisation of simple possession, or to the penalties associated with drug offences, such differentiation remains a core problem for policymakers. In this commentary, taking 91 different jurisdictions into consideration, we identify five different approaches to distinguishing personal use from supply: four of these involved quantification of an amount of drug (whether in weight or number of doses). The other approach relied on case-by-case judgement. Drawing upon survey data of drug use from nine countries, we provide an example of how the quantity bears little resemblance to drug use patterns, and does not take heterogeneity of drug use into account. While the non-quantified approach can lead to discriminatory and racialised policing, all of the quantification approaches also pose problems, largely concerned with arbitrary amounts. There appears to be no perfect way to differentiate possession for personal use from intentions to supply. This commentary opens up a number of important policy-relevant research questions given this central feature of drug policy design.