Intended for healthcare professionals


What would an evidence based drug policy be like?

BMJ 2014; 349 doi: (Published 09 December 2014) Cite this as: BMJ 2014;349:g7493
  1. Nicola Singleton, visiting researcher,
  2. John Strang, professor
  1. 1 National Addiction Centre (Institute of Psychiatry and The Maudsley), King’s College London, London SE5 8AF, UK
  1. Correspondence to: N Singleton nicolasingleton22{at}

Policy must move beyond evidence based to evidence infused to produce public good

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.

Openness to negative evidence

A common theme from recent reports is that approaches that view drug problems as a public health rather than a criminal justice concern tend to be more effective. The negative consequences arising from the criminalisation and imprisonment of drug users have been well documented,10 and, as the international comparator report points out, the evidence from countries with different approaches suggests no massive upsurge of harms.1 Nevertheless, concerns about possible negative consequences persist, and calls for change are often dismissed out of hand. The results from individual studies should rightly be scrutinised and tested. However, if the UK government is serious about having evidence based policies, then there must be the political will to accept the evidence even if it is at odds with prior beliefs. The unwillingness to accept the evidence from independent bodies such as the National Institute of Health and Care Excellence (NICE) and the Advisory Council on the Misuse of Drugs suggests a failure of process.

We are seeing new drugs emerge alongside new patterns of use, supply routes, and opportunities for intervention. Consequently, new approaches need to be developed and the evidence base must continue to grow and be updated to reflect the new realities. As circumstances and contexts change, interventions may not always work as expected, so regular reviews of effectiveness are needed and policy revised to optimise benefits.

An evidence based drug policy, therefore, might be better conceived as evidence infused policy. Such a policy would have clear, achievable objectives but would recognise the inevitability of changes as a result of the drug policies themselves and changes in the wider social context.4 11 Evidence infused policy would monitor the change in harms and benefits over time and makes changes in response. Part of such an approach would be the discontinuation of interventions shown to be no longer effective or with adverse effects. Similarly, it will be necessary to embark on innovative approaches with only limited evidence. In these circumstances evaluation will be essential, as will be the requirement to act on the results. Stopping a programme should not be viewed as a policy failure but policy maturity, and an example of the dynamic nature of the science-policy relationship.

For such an approach to be successful requires a policy making environment akin to that of a “learning organisation,” in which politicians, policy makers, and practitioners are open to and seek out evidence of failure as well as success. In addition, honest and open minded engagement is needed from the public and the media, with an understanding that policy must adapt and change to meet new challenges and changing circumstances.


Cite this as: BMJ 2014;349:g7493


  • Editorial, doi:10.1136/bmj.g6580
  • Competing interest statement: We have read and understood BMJ policy on declaration of interests and declare the following interests: NS was director of policy and research at the UK Drug Policy Commission, for which JS was a commissioner. JS has been/is a member of the scientific advisory boards for the European Monitoring Centre for Drugs and Drug Addiction and UN Office on Drugs and Crime. JS has worked with various drug companies to consider and test potential new treatments for addictions and related problems. NS has been contracted to undertake a research project for the Beckley Foundation, which campaigns for drug policy reform.

  • Provenance and peer review: Commissioned; not externally peer reviewed.


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