Do drug programs really work?

Lessons from current drug prevention programmes

We all know the sad stories of celebrities destroyed by illegal drugs. Occasionally, there is a glimmer of hope, as a star is coming out of rehab and staying clean. These top media scoops might make the headlines, but they should not influence debates about how to help addicts. Yet, public opinion is easy to be swayed; emotions, prejudices and personal experiences make it difficult to develop effective policies and programmes based on objective evidence. Fortunately, there is quite a bit of evidence out there. One of the best resources is the European Monitoring Centre for Drugs and Drug Addiction, the EMCDDA, which publishes full reviews of the evidence and current best practice in the areas of prevention, therapy and harm reduction.

Prevention’s effectiveness

Unfortunately, the evidence base for prevention programmes is rather patchy. For example, there is no consistent proof that mass media campaigns help to modify drug use; not if they are standalone campaigns, at least. On the other hand, a Cochrane review found that comprehensive family-oriented prevention is likely to reduce cannabis use.

School-based programmes also seem good at reducing or delaying illegal drug use, but students need more than just lessons about drugs. They respond better to their peers; they are influenced by their social networks and are more able to resist drugs if they develop good life skills.
One systematic review shows the benefits of getting the local community, school and family all involved together in prevention and reduction programmes.

Tentative treatements

The evaluation of treatment programmes is also mixed. For heroin, at least, the evidence is compelling: diverse treatment options are effective. Methadone or buprenorphine, including for pregnant women, help to keep addicts on treatment; they reduce opioid use, HIV infection and mortality. Adding psycho-social interventions and case management into the mix also works.

The evidence for the treatment of cocaine addition is inconclusive. We still do not know whether treatment with antipsychotic drugs, anticonvulsivants or psychostimulants really works. Some pharmacological approaches, such as the use of antidepressants or dopamine agonists, and cognitive/behavioural psycho-social interventions do seem to help, however.

And what about that rehab clinic for the rich and famous? Unfortunately, the jury is still out on whether residential stays really work that well.

When prevention and treatments fail, you are left with little choice. All you can do is try to limit the harm illegal drug users do to themselves. As these addicts usually want anonymity, the programmes are difficult to monitor; research and experimental control trials are difficult.

Nevertheless observational studies and reviews provide enough evidence to conclude that several interventions are likely to be beneficial: These include needle/syringe exchange, which reduce risky injection practices and HIV infection, drug consumption rooms, which reduce risky injection practices, continuity of treatments from prison to community, which reduce mortality, and opiate substitution plus needle exchange, which reduce incidence of HIV and HCV.

For example, Switzerland set up a comprehensive continuous evaluation of national harm reduction policy in 1991, followed up in 2003. It included numerous studies and surveys, some repeated over time. The cumulative evidence reveals the widespread acceptance of the sale and distribution of syringes, no effect on numbers of drug users entering treatment, a decrease in new HIV cases and in needle sharing, now at very low levels. It also reveals no increase in number of injecting users as well as a reduction in syringe demand. Finally, the Availability of syringes remained high, risk behaviours and HIV incidence low, over time.

Beyond evidence

Despite the growing evidence base, policy-makers must remember this: context is everything. Most of the evidence comes from controlled experimental studies on the efficacy of programmes; they do not look at their effectiveness in the real world. But the implementation of a programme is also crucially important.

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Moreover, interventions tend to work together. For example, in an area with high levels of addiction school-based prevention may coordinate activities with a local needle exchange and a treatment centre. These combinations may deliver results where a single programme would not.

Experience suggests that comprehensive and coherent drug policies are most likely to succeed. Although it is generally impossible to evaluate policies with randomised controlled trials, it is straightforward to gather and analyse data from many sources, including specific surveys, routine statistics such as drug treatment statistics, mortality statistics, police and justice statistics, etc. Over time this cumulative evidence will reveal whether a policy or programme is truly effective. In this way policy-makers can avoid subjective and misinformed debates and ensure the consolidation of firm action to tackle illicit drug addiction.

Françoise Dubois-Arber

Françoise was formerly associate professor at the Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Switzerland. She is an expert in evaluation of public health policy and in prevention programmes.

This article is the edited version of a piece that was first published in Science in the Public Interest vol. 2: Addictions and Their Brain Reward Systems, published by SciCom– Making Sense of Science.

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