The nature of benzodiazepine dependence among heroin users in Sydney, Australia

Aims. To determine the extent to which heroin users meet criteria for benzodiazepine dependence, to examine the appropriateness of these criteria for assessing benzodiazepine dependence among this population, and to assess what other substance use, depressive and anxiety disorders are associated with benzodiazepine dependence. Design. Cross-sectional survey. Setting. Sydney, Australia. Participants. Two hundred and twenty-two heroin injectors recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth. Findings. Twenty-six per cent (52/202) of those who had used benzodiazepines received a life-time diagnosis of benzodiazepine dependence, with 22% of current benzodiazepine users being dependent. A principal components analysis revealed that a unidimensional construct underlies the benzodiazepine dependence syndrome. Those respondents with life-rime benzodiazepine dependence were more likely than others to meet criteria for anxiety or depressive disorders. Conclusions. The inclusion of the benzodiazepine dependence syndrome in DSM-III-R (and DSM-IV) is justified. A disturbingly high proportion of heroin users meet the criteria for benzodiazepine dependence, a condition that should be regarded as a significant marker for co-morbidity among this group.