Suicide among drug addicts in the UK

BACKGROUND: The extent of suicide among addicts in the UK has not been sufficiently examined. AIMS: To examine suicide trends among registered addicts in the UK over a 25-year period. METHOD: We quantified suicide using International Classification of Diseases (ICD) external death codes E950-959, calculated annual age-standardised suicide rates, standardised mortality ratios (SMRs) and described trends in methods of suicide and drug overdose suicides in five successive cohorts of registered addicts. RESULTS: Male and female suicide rates are 69.0 and 44.8 per 100,000 person-years, respectively. There was a consistent decline in suicide rate throughout the 25-year period. Among males, the SMR for suicide declined from 17.2 in 1968-1972 to 4.4 in 1988-1992 (SMR ratio = 3.9, 95% CI = 2.5-6.1); among females it declined from 52.6 to 11.3 in the same period (SMR ratio = 4.7, 95% CI = 1.9-10.8). Drug overdose was the most common method of suicide, accounting for 45% of cases. Significant increase in antidepressant (percentage difference = 23.5%, 95% CI = 15.2-31.8) and methadone (percentage difference = 11.0%, 95% CI = 0.5, 21.5) overdose in 1988-1992 compared with 1968-1972 was reported. CONCLUSIONS: The findings confirm that addicts are still at higher risk of suicide than the general population and that prescribed drugs, notably antidepressants and methadone, influence this heightened risk.