Factor structures for DSM-IV substance disorder criteria endorsed by alcohol, cannabis, cocaine and opiate users: results from the WHO reliability and validity study

Aims. The factor structure of DSM-IV substance disorder criteria is examine d among alcohol, cannabis, cocaine and opiate users to determine the dimens ionality of abuse and dependence criteria within each of these drug classes and whether a common construct can be generalized across drug classes. Des ign. 12-month criterion prevalence was assessed as part of the World Health Organization's Study on the Reliability and Validity of the Alcohol and Dr ug Use Disorder Instruments in various settings at eight sites around the w orld wing the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). A majority of respondents were recruited from non-treatment settings, in ad dition to exploratory factor analysis, confirmatory factor analysis was use d to analyse factor structures using weighted least square methods and tetr achoric correlation matrices. Multi-sample analysis techniques were used to model differences between drug-classes. Findings. In the full data analyse s identified a single factor solution for each user population and across u ser populations. However, analyses of data from users reporting low to mode rate symptomatology identified a two-dimensional construct among alcohol, c annabis and opiate users consisting of a major "dependence" factor and a le sser "abuse" factor. In addition, results showed that neither the abuse cri terion "(A2) use in physical hazardous situations" or the dependence criter ion "(D7) use despite knowledge of psychological/physical problems" were ce ntral to the latent construct in ally of the user populations, except for D 7 among alcohol users. Conclusions. The multi-dimensional results found amo ng users with low to moderate symptomatology indicate that: (1) previous re sults from relatively homogeneous populations may have been biased towards lesser order solutions, and that (2) the DSM-IV substance disorder criteria describe at least two distinct phenomena, supporting the current DSM-IV or ganization of substance disorder criteria. Further work need to evaluate wh ether prevalent symptoms are present in random or predictable combinations, whether combinations reflecting a specific hierarchy of severity call be i dentified, and whether incident symptoms are accumulated in a predictable p attern, within specific user populations and across user populations.