Long-term mortality, remission, criminality and psychiatric comorbidity of heroin dependence: 11-year findings from the Australian Treatment Outcome Study

Aims: To determine the long-term mortality, remission, criminality and psychiatric comorbidity during 11years among heroin-dependent Australians. Design: Longitudinal cohort study. Setting: Sydney, Australia. Participants: A total of 615 participants were recruited and completed baseline interviews between 2001 and 2002. Participants completed follow-up interviews at 3, 12, 24 and 36months post-baseline, and again at 11years post-baseline; 431 (70.1%) of the original 615 participants completed the 11-year follow-up. Measurements: Participants were administered the Australian Treatment Outcome Study (ATOS) structured interview, addressing demographics, treatment history, drug use, heroin overdose, criminality, health and mental health at all interviews. Overall, 96.1% of the cohort completed at least one follow-up interview. Findings: At 11years, 63 participants (10.2%) were deceased. The proportion of participants who reported using heroin in the preceding month decreased significantly from baseline (98.7%) to 36-month follow-up (34.0%; odds ratio=0.01; 95% confidence interval=0.00, 0.01) with further reductions evident between 36months and 11years (24.8%). However, one in four continued to use heroin at 11years, and close to one-half (46.6%) were in current treatment. The reduction in current heroin use was accompanied by reductions in risk-taking, crime and injection-related health problems, and improvements in general physical and mental health. The relationship with treatment exposure was varied. Major depression was associated consistently with poorer outcome. Conclusions: In an 11-year follow-up of patients undergoing treatment for heroin dependence, 10.2% had died and almost half were still in treatment; the proportion still using heroin fell to a quarter, with major depression being a significant predictor of continued use.