What would an evidence based drug policy be like?

In their foreword to the UK Home Office’s comparison of drug policies in various countries, government ministers stated that “the UK will continue to advocate a balanced, evidence-based approach to the misuse of drugs internationally.”1 In a subsequent Commons debate there was cross party support for the motion that “this House . . . believes that an evidence-based approach is required in order for . . . the Government to pursue the most effective drugs policy.”2 This flurry of attention raises the question: what would an evidence-based drug policy look like?

Although the prohibitionist legislative framework is the main focus of calls for reform, it is just one element of policy. Most countries have drug policies that include activities to reduce the demand for drugs, the harms associated with their use, and their supply. Evidence-based policy suggests a neat menu of well evidenced interventions from which a government can select the right mix for its circumstances. However, in common with many areas of social policy, drug use is multifaceted and “what works” is rarely clear cut and often contested. Both the nature and patterns of use, and the responses to these, vary between countries and over time; the interventions that will be appropriate and effective will therefore also vary. Nevertheless, it is important that the available evidence is considered if policies are to be effective, provide value for money, and avoid unintended consequences.

Several recent publications have sought to pull together the current evidence, both positive and negative, for drug policy.3 4 These, and the Home Office’s study, highlight the evidence of benefit from a range of interventions, particularly treatments and programmes of harm reduction for people with problematic opiate use.1 Unfortunately, the evidence base for many other common interventions, in particular in law enforcement and drug education, is weak and some may even do harm.

These reports also highlight several other important challenges for evidence based policy making. Firstly, whether something can be considered successful depends on the goal. For example, strong evidence exists for the effectiveness of heroin assisted treatment in reducing the harms associated with heroin use among people with entrenched problems for whom other forms of treatment have failed.5 However, other interventions will be required to support people addicted to other drugs or seeking to maintain abstinence. Secondly, what has been shown to work in one context may not readily transfer to another. This is shown by the varying success of drug courts. Although the evidence is largely positive in the US, the picture is mixed and much less positive elsewhere, including in the UK.6 This underlines the importance of continuing to review effectiveness and develop robust indicators of outcomes once policies have been implemented. The same is true for innovative programmes where the evidence is promising but as yet limited, as in the case of take-home naloxone.7 Public policy and criminal justice interventions should be studied and trialled using scientific methods familiar in health8 9; this will generate tomorrow’s better evidence.