title: Screening of cannabis-related problems among youth: the CPQ-A-S and CAST questionnaires.
abstract: BACKGROUND
  Cannabis use among young people is a significant problem, making particularly necessary validated screening instruments that permit secondary prevention. The purpose of this study was to analyze and compare the psychometric properties of the CAST and CPQ-A-S questionnaires, two screening instruments specifically addressing the youth population.
  
  
  METHODS
  Information was obtained on sociodemographics, frequency of substance use, psychopathological symptoms and cannabis-use problems, and the CPQ-A-S and CAST were applied, as well as an infrequency scale for discarding responses made randomly. The sample was made up of 144 young people aged 16 to 20 that had used cannabis in the last month, of which 71.5% were boys. Mean age of the sample was 17.38 years (SD = 1.16).
  
  
  RESULTS
  The results show that from the psychometric point of view both the CAST and the CPQ-A-S are good screening instruments.
  
  
  CONCLUSIONS
  The CAST is shorter and presents slightly better internal consistency than the CPQ-A-S. Both instruments show high sensitivity and specificity in the detection of young people dependent on cannabis according to the DSM IV-TR criteria. The CPQ-A-S appears to show greater capacity for detecting psychopathological distress associated with use. Both questionnaires yield significant odds ratios as predictors of frequent cannabis use and of the DSM IV-TR abuse and dependence criteria. In general, the CPQ-A-S emerges as a better predictor than the CAST.
authors.affiliation: Addictive Behaviours Research Group, Department of Psychology, University of Oviedo, UCA, Facultad de Psicología, Pza Feijoo s/n, Oviedo, Asturias, Spain. fernandezasergio@uniovi.es
authors.forename: Sergio
authors.initials: S
authors.lastname: Fernandez-Artamendi
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Fernández-Hermida
authors.forename: José
authors.initials: J
authors.lastname: Muñiz-Fernández
authors.forename: Roberto
authors.initials: R
authors.lastname: Secades-Villa
authors.forename: Gloria
authors.initials: G
authors.lastname: García-Fernández
mesh_terms: D000293:Adolescent; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000175:diagnosis*; D011594:Psychometrics / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019966:Substance-Related Disorders / Q000175:diagnosis; D011795:Surveys and Questionnaires; D055815:Young Adult