title: The influence of age and gender on the likelihood of endorsing cannabis abuse/dependence criteria.
abstract: BACKGROUND
  Higher prevalence rates of cannabis abuse/dependence and abuse/dependence criteria in 18-24year old versus older cannabis users and in males versus females might reflect true differences in the prevalence of these disorders across age and gender or, alternatively, they could arise from age- and gender-related measurement bias. To understand differences in endorsement across important subgroups, we examined the influence of age and gender simultaneously on the likelihood of endorsement of the various abuse/dependence criteria.
  
  
  METHODS
  The sample consisted of 1603 adult past year cannabis users participating in the National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a U.S. population study (39.6% aged 18-24; 62.1% male). Past year DSM-IV cannabis abuse/dependence criteria and withdrawal were assessed with the AUDADIS-IV. A restricted factor analysis with latent moderated structures was used to detect measurement bias.
  
  
  RESULTS
  Although cannabis abuse and dependence diagnoses and various individual abuse/dependence criteria showed different prevalence rates across younger and older male and female cannabis users, none of the items showed uniform or non-uniform measurement bias with respect to age or gender.
  
  
  CONCLUSIONS
  The results indicate that, although prevalence rates of cannabis abuse/dependence criteria differ across age and gender, past year abuse/dependence criteria function similarly across these groups. It can thus be concluded that the criteria are applicable to younger and older, as well as male and female, adult cannabis users.
authors.affiliation: VU University, Department of Developmental Psychology and EMGO Institute for Health and Care Research, Amsterdam, The Netherlands.
authors.forename: Monique J
authors.initials: MJ
authors.lastname: Delforterie
authors.affiliation: Research Institute of Child Development and Education, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Hanneke E
authors.initials: HE
authors.lastname: Creemers
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: Arpana
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: Addictions Dept, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lynskey
authors.affiliation: Department of Methods and Statistics, Faculty of Social Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Jak
authors.affiliation: VU University, Department of Developmental Psychology and EMGO Institute for Health and Care Research, Amsterdam, The Netherlands. Electronic address: a.c.huizink@vu.nl.
authors.forename: Anja C
authors.initials: AC
authors.lastname: Huizink
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Age; Cannabis abuse/dependence; DSM-IV; Factor analysis; Gender; Measurement bias