"With respect to the group of those treated uninterruptedly during four years, a strong decrease in the incidence and prevalence rates of overall criminal implication for both intense and moderate offenders was found. As to the type of offense, similar diminutions were observed for all types of offenses related to the use or acquisition of drugs. Not surprisingly, the most pronounced drop was found for use/possession of heroin. In accordance with self-reported and clinical data (Blaettler, Dobler-Mikola, Steffen, & Uchtenhagen, 2002; Uchtenhagen et al., 1999), the analysis of police records suggests that program participants also tend strongly to reduce cocaine and cannabis use probably because program participants dramatically reduced their contacts with the drug scene when entering the program (Uchtenhagen et al., 1999) and were thus less exposed to opportunities to buy drugs. Consequently, their need for money is not only reduced with regard to heroin but also to other substances. Accordingly, the drop in acquisitive crime, such as drug selling or property crime, is also remarkable and related to all kinds of thefts like shoplifting, vehicle theft, burglary, etc. Detailed analyses indicated that the drop found is related to a true diminution in criminal activity rather than a more lenient recording practice of police officers towards program participants.
"On average, males had higher overall rates than females in the pretreatment period. However, no marked gender differences were found with regard to in-treatment rates. Taken as a whole, this suggests that the treatment had a somewhat more beneficial effect on men than women. This result is corroborated by self-report data (Killias et al., 2002). With respect to age and cocaine use, no relevant in-treatment differences were observed. As to program dropout, after one year, about a quarter of the patients had left the program, and after four years, about 50% had left. Considering the high-risk profile of the treated addicts, this retention rate is, at least, promising."
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.