Epidemiologic differences in drug dependence - A US-UK cross-national comparison

Background. Published epidemiologic survey statistics do not allow direct cross-national comparison of drug dependence in the US and the UK, primarily because of a lack of uniformity across case definitions and methods of case ascertainment. Aims. The current study sought to re-estimate these prevalence values after calibration of case definitions (i. e., imposing methodological constraints to unify case definitions), to identify suspected determinants, and also to investigate symptom profiles among active cases. Method. Analyses of data from the US National House-hold Survey on Drug Abuse and the UK Survey of Psychiatric Morbidity were conducted. Prevalence of active drug dependence symptoms was estimated. Logistic regression analysis was used to estimate the magnitude of the association between suspected socio-demographic variables and drug dependence. Results. The prevalence of drug dependence was an estimated 1.4% in the US and 0.5% in the UK. This difference was somewhat attenuated when the effect of living in an urban setting was controlled. Symptom profiles among active cases were very similar. In both countries, being male, non-married, of a low socio-economic status (SES), and living in an urban setting were associated with an increased occurrence of drug dependence. Conclusion. There are US-UK differences in prevalence of active drug dependence beyond what available statistics imply and some of this difference can be explained by variations associated with living in urban and rural conditions.