The impact of treatment on 3 years' outcome for heroin dependence: findings from the Australian Treatment Outcome Study (ATOS)

Aim To examine the impact of treatment for heroin dependence on drug use, injection-related risk-taking, health problems, criminality and general physical and mental health over 3 years among heroin-dependent Australians. Design Longitudinal prospective cohort study. Participants A total of 615 heroin users enrolled in the Australian Treatment Outcome Study; 94.5% of the sample completed at least one follow-up interview over 36-month follow-up. Findings The proportion who reported using heroin in the preceding month continued to decrease significantly from baseline to 24-month follow-up (99% versus 35%), with this rate remaining stable to 36-month follow-up. The reduction in heroin use was accompanied by reductions in other drug use. There were also substantial reductions in risk-taking, crime, injection-related health problems and improvements in general physical and mental health. Positive outcomes were associated with more time in maintenance therapies and residential rehabilitation and fewer treatment episodes. Time spent in detoxification was not associated with positive outcomes. Major depression was also associated consistently with poorer outcome. Conclusions At 3 years, there were impressive reductions in drug use, criminality, psychopathology and injection-related health problems following treatment exposure.