HAT was first tested in the Swiss National Cohort Study between 1994 and 1996. The results indicated a substantial improvement in the dependent users' physical and mental health and also in their social situation. In addition, a massive reduction in criminal behaviour was observed.

At the end of 2009, 1356 patients were undergoing HAT at 21 outpatient centres and in 2 prisons.

HAT is now being carried out at centres in Basle, Bern, Biel, Brugg, Burgdorf, Chur, Geneva, Horgen, Lucerne, Olten, Reinach, Schaffhausen, Solothurn, St. Gallen, Thun, Winterthur, Wetzikon, Zug, Zürich and in two prisons Oberschöngrün (canton Solthurn) and Realtà (canton Graubünden).

Legal foundations

Following the favourable outcome of the National Cohort Study, HAT became firmly established within the "therapy" arm of the Federal Council's fourfold approach with the adoption of the urgent Federal Decree of 9th October 1998 and the Ordinance of 8th March 1999 concerning the Medical Prescription of Heroin. In June 2003, the term of the Federal Decree - which is an amendment of the Narcotics Law (Art. 8 Paragraphs 6-8) - was extended until 2009 by the National Council and the Council of States. HAT is in no way intended as a replacement for other types of treatment, either based on abstinence or involving the use of other substances (e.g. methadone).

Since 1.1.2010 the HAT is definitely rooted in the law on drugs as therapy.

Treatment objectives and Results

The Federal Council fixed the following objectifs within the Ordinance concerning the Medical Prescription of Heroin of 8th march 1999:

• Sustained commitment to treatment
• Improvement in physical and mental health status
• Improvement in social integration (fitness for work, reduced contact with the drug scene, decrease in criminal behaviour)
• Permanent abstinence from opiate consumption as a long-term goal

Results

In many cases, patients' physical and mental health has improved, their housing situation has become considerably more stable, and they have gradually managed to find employment. Numerous participants have managed to reduce their debts. In most cases, contacts with addicts and the drug scene have decreased. Consumption of non-prescribed substances declined significantly in the course of treatment.

Dramatic changes have been seen in the situation regarding crime. While the proportion of patients who obtained their income from illegal or borderline activities at the time of enrolment was 70%, the figure after 18 months of HAT was only 10%.

Each year, between 180 and 200 patients discontinue HAT. Of these patients, 35-45% are transferred to methadone maintenance, and 23-27% to abstinence-based treatment.

The average costs per patient-day at outpatient treatment centres in 1998 came to CHF 51. The overall economic benefit - based on savings in criminal investigations and prison terms and on improvements in health - was calculated to be CHF 96. After deduction of costs, the net benefit is CHF 45 per patient-day.

International developments

HAT studies have been initiated in the Netherlands and Germany. Similar projects are in preparation in other countries.