Accidental and deliberate overdose among opiate addicts in methadone maintenance treatment : are deliberate overdoses systematically different?

The frequency of accidental or deliberate overdose was investigated among 200 opiate addicts in methadone substitution treatment in clinics in Edinburgh and south London. One hundred and three of the participants reported a mean of 3.4 overdoses, with 71 (69%) reporting that their most recent overdose was accidental, 27 (26%) deliberate - the remainder were uncertain. Those whose last overdose was deliberate were more likely to have been prescribed diazepam at that time and were more depressed at the time of interview. Differentiation by self-reported reason for overdose suggests that treatment providers should distinguish between accidental and deliberate overdose in developing overdose prevention strategies.