Abstract
Evaluated the homogeneity of the elements of the Substance Dependence Syndrome as applied to benzodiazepines (BZDs) by Rasch modelling. The Rasch scaling model was applied to data obtained by administering the Schedules for Clinical Assessments in Neuropsychiatry substance dependence sections. Subsequently, Rasch-homogeneous sets of Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) and International Classification of Diseases (ICD) 10th edition BZD dependence criteria were assessed for subject and item discriminability. To support their construct validity a theoretical rationale was formulated based on the Rasch scale values. Ss were 599 outpatient BZD users. Findings show that only particular subsets of the DSM-III-R and ICD-10 BZD dependence criteria met the requirements for Rasch-homogeneity, which appears to be due to medical aspects of BZD use. The subject and item discriminability results were sufficiently good. The DSM-III-R and ICD-10 BZD dependence constructs may need to be redefined. The use of a BZD dependence severity model based on a Rasch-homogeneous scale appears to have greater clinical value than a dichotomous diagnostic model based on an arbitrary cut-off point.
