title: The Severity of Dependence Scale (SDS) in an adolescent population of cannabis users: reliability, validity and diagnostic cut-off.
abstract: The Severity of Dependence Scale (SDS) is a five-item scale that has been reported to be a reliable and valid screening instrument for dependence and a measure of dependence severity in adults across several substance classes. To date no data have been reported on its performance in a population of adolescent cannabis users. The current study assessed the psychometric properties of the SDS in a community sample of 14-18-year-old adolescent cannabis users (n=100). Internal consistency (alpha=0.83) and test-retest coefficients (ICC=0.88) were high and a principal components analysis of the scale found all items to load on a single factor. Total SDS score correlated significantly with frequency of cannabis use and number of DSM-IV dependence criteria met, indicating good concurrent validity. Receiver Operating Characteristic curve analysis was used to determine the most appropriate SDS cut-off score for use as an indicator of cannabis dependence, with optimal discrimination at an SDS score of 4. These findings indicate that the SDS is a reliable and valid measure of severity of cannabis dependence among adolescents, has high diagnostic utility, and that an SDS score of 4 may be indicative of cannabis dependence.
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, Sydney, NSW 2052, Australia. g.martin@unsw.edu.au
authors.forename: Greg
authors.initials: G
authors.lastname: Martin
authors.forename: Jan
authors.initials: J
authors.lastname: Copeland
authors.forename: Peter
authors.initials: P
authors.lastname: Gates
authors.forename: Stuart
authors.initials: S
authors.lastname: Gilmour
mesh_terms: D000293:Adolescent; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D002189:Marijuana Abuse / Q000145:classification / Q000175:diagnosis* / Q000523:psychology; D008403:Mass Screening / Q000706:statistics & numerical data; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data; D012372:ROC Curve; D015203:Reproducibility of Results; D012647:Self-Assessment; D013223:Statistics as Topic