Petry (Reference Petry2006) provides a welcome review of contingency management in substance misuse settings and expresses surprise that it has not been employed more widely in Europe, particularly given the greater acceptance of ‘harm minimisation’ here than in the USA, where contingency management has been championed. This is broadly true but some UK drug services are experimenting with interventions informed by reinforcement principles.

The injectable opiate clinic at the Chelsea and Westminster Hospital in London has for some years used reinforcement principles to target illicit opiate and crack cocaine use. Urine samples are regularly tested and the results used alongside clinical judgement to determine the proportion of a client's total daily opiate dose which may be administered intravenously as opposed to orally. In this way, access to injectable rather than oral opiate preparations is the ‘reward’ for positive behaviour. Staff increase or decrease the injectable proportion of the client's prescription depending on the client's stability.

As a first step towards developing an intervention study (Medical Research Council, 2000) we completed qualitative interviews with staff and clients to assess attitudes towards the further development of reinforcement methods. Staff and clients both cautiously supported reinforcement principles, and staff perceived clients to be more stable and less likely to use illicit substances under the present reinforcement scheme. Nevertheless, challenges were also highlighted. Most staff had reservations about developing voucher-based contingency management, citing possible increased workloads and a potential for damage to staff–client relationships. Despite a strong commitment to harm minimisation strategies at the clinic, some staff also had ethical objections to the development of voucher-based contingency management.

Our study was small and more research is required to explore the feasibility of voucher- or prize-based contingency management. However, as Petry emphasises, contingency management strategies have a good evidence base in a complex and challenging client group where positive outcomes are elusive. It is surely time to evaluate whether contingency management has a place in UK drug treatment services. Our work suggests that debate about the theoretical basis of contingency management and its ethical implications is needed to win support for experimentation among hard-pressed drug treatment workers in the UK.