Substance Dependence Severity Scale (SDSS): reliability and validity of a clinician-administered interview for DSM-IV substance use disorders.

No existing diagnostic interview assesses severity of dependence based on DSM-IV criteria across a range of substances. The Substance Dependence Severity Scale (SDSS) was designed to serve this purpose, consisting of substance-specific scales of both severity and frequency of DSM-IV criteria. This study investigated the reliability and validity of the SDSS. The test-retest reliability of the SDSS in 175 (112 male and 63 female) treated substance users ranged from good to excellent for alcohol, cocaine, heroin and sedatives (interclass correlation coefficients (ICCs)=0.75-0.88 for severity, 0.67-0.85 for frequency). Results for cannabis were lower, ranging from fair to good (ICCs=0.50-0.62). Results for joint rating and internal consistency reliability were comparable to test-retest findings. In addition to indicators of concurrent validity, scale applications are presented and discussed.