THE SEVERITY OF DEPENDENCE SCALE (SDS) - PSYCHOMETRIC PROPERTIES OF THE SDS IN ENGLISH AND AUSTRIAN SAMPLES OF HEROIN, COCAINE AND AMPHETAMINE USERS

The Severity of Dependence Scale (SDS) was devised to provide a short, easily administered scab which can be used to measure the degree of d ependence experienced by users of different types of drugs. The SDS co ntains five items, all of which are explicitly concerned with psycholo gical components of dependence. These items are specifically concerned with impaired control over drug taking and with preoccupation and anx ieties about drug use. The SDS was given to five samples of drug users in London and Sydney. The sampler comprised users of heroin and users of cocaine in London, and users of amphetamines and methadone mainten ance patients in Sydney. The SDS satisfies a number of criteria which indicate its suitability as a measure of dependence. All SDS items loa d significantly with a single factor, and the total SDS score was extr emely highly correlated with the single factor score. The SDS score is related to behavioural patterns of drug taking that are, in themselve s, indicators of dependence, such as dose, frequently of use, duration of use, daily use and degree of contact with other drug users; it als o shows criterion validity in that drug users who have sought treatmen t at specialist and non-specialist agencies for drug problems have hig her SDS scores than non-treatment samples. The psychometric properties of the scale were good in all five samples, despite being applied to primary users of different classes of drug, using different recruitmen t procedures in different cities in different countries.