"Finally, the analysis of the reasons for interrupting treatment revealed that, even in the group of those treated for less than one year, the majority did not actually drop out of the program but rather changed the type of treatment, mostly either methadone maintenance or abstinence treatment. Knowing that methadone maintenance treatment – and a fortiori abstinence treatment – is able to substantially reduce acquisitive crime, the redirection of heroin maintenance patients toward alternative treatments is probably the main cause for the ongoing reduction or at least stabilization of criminal involvement of most patients after treatment interruption. Thus the principal post-treatment benefit of heroin maintenance seems to be its ability to redirect even briefly treated high-risk patients towards alternative treatments rather than back 'on the street'."

Source

Ribeaud, Denis, "Long-term Impacts of the Swiss Heroin Prescription Trials on Crime of Treated Heroin Users," Journal of Drug Issues, Talahassee, FL: University of Florida, Winter 2004.