Around 3,000 heroin addicts currently receive opioids such as methadone, buprenorphine or morphine as part of their treatment in the Canton of Zurich. The number of these so-called substitution treatments has remained constant since their introduction in the 1990s. Long-term courses of therapy with methadone or other opioids evidently reduce the consumption of illegal drugs among patients addicted to heroin. Although the beginning of this kind of treatment also leads to a reduction in the consumption of alcohol, more patients drink alcohol more frequently today than in previous decades. This is shown in a new long-term study conducted by researchers from the University Psychiatric Hospital and the University of Zurich.
Heroin and cocaine consumption markedly reduced
The study includes data on nearly 9,000 patients with a heroin addiction who underwent substitution therapy in the Canton of Zurich between 1998 and 2014. They already consumed sustainably less heroin or cocaine — and somewhat less alcohol — from the beginning of the treatment. Moreover, the proportion of patients who consumed heroin frequently (at least five days per week) more than halved over the 17-year study period (from 14.4 to six percent), and the number of frequent cocaine consumers shrank from 8.5 to 4.9 percent. The results also demonstrate that the decrease in heroin consumption went hand in hand with an improved social situation for the patients.