Choosing a cut-off on the Severity of Dependence Scale (SDS) for amphetamine users.

In order to ascertain a cut-off score on the Severity of Dependence Scale (SDS) which is indicative of clinically significant amphetamine dependence, 327 regular amphetamine users were administered the SDS, along with the "Disorders resulting from the use of psychoactive substances" section of the Composite International Diagnostic Interview (CIDI) for DSM-III-R. Receiver operating characteristic (ROC) analysis was used in order to determine which cut-off score on the SDS allowed the best trade-off between sensitivity and specificity, when calibrated against the presence or absence of a DSM-III-R diagnosis of severe amphetamine dependence. Results suggest that the SDS has high diagnostic utility, and that a score of greater than four on the scale is indicative of problematic amphetamine use.