Long-termmortality, 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 11 years 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 36 months post‐baseline, and again at 11 years 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 11 years, 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 36 months and 11 years (24.8%). However, one in four continued to use heroin at 11 years, 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.