According to newly published research Switzerland's policy of offering heroin addicts substitution treatment with methadone or buprenorphine has led to a decline in the number of new heroin users in Zurich.
Switzerland has implemented various policies to try and reduce harm to dependent heroin users, including needle-exchange services, low-threshold methadone programmes, and heroin-assisted treatments.
But many critics believe such policies in fact lead to a growing number of new drug users and only serve to extend the period of heroin addiction.
Researchers Carlos Nordt and Rudolf Stohler from the Psychiatric University Hospital in Zurich were eager to examine the trends and the prevalence of problem heroin use in Switzerland and in order to do so they analysed data from 7256 patients in Zurich who presented for substitution treatments with methadone or buprenorphine over a 13 year period from 1991 to March, 2005.
It appeared that every second person began their first substitution treatment within 2 years of starting to use heroin regularly.
The incidence of heroin use rose steeply, starting with about 80 people in 1975, culminating in 1990 with 850 new users, and declining substantially to about 150 users in 2002.
Two-thirds of those who had left substitution treatment programmes re-entered within the next 10 years and the population of problematic heroin users declined by 4% a year.
The researchers compared the findings with the situation with heroin use in the UK, Italy, and Australia, which has continued to rise.
Dr. Nordt says the harm reduction policy of Switzerland and its emphasis on the medicalisation of the heroin problem seems to have contributed to the image of heroin as unattractive for young people.
The Swiss population supported the drug policy and the image of heroin use as a rebellious act was changed to an illness that needs therapy.
Nordt believes heroin has become a 'loser drug' and its attractiveness has diminished for young people.
He believes the model could enable the study of incidence trends across different countries and so encourage needed assessments of the effects of different drug policies.
The researchers say the data could not confirm an increase of heroin incidence as expected by the critics of the liberal Swiss drug policy.