To determine whether cannabis abuse and dependence measure a unitary dimension of cannabis use disorder, large representative samples of the general population are needed that do not restrict variability in cannabis use or dependence and that use current measures of cannabis use and disorder criteria to reduce substantially the risk of recall bias. Accordingly, the purpose of the present study was to determine whether the DSM-IV abuse and dependence criteria defined a cannabis use disorder continuum using a large (n=43,093) nationally representative sample of the U.S. population, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). IRT methodology was used: (1) to examine the ability of each 12-month DSM-IV cannabis abuse and dependence criterion to discriminate between individuals across the cannabis use disorder continuum among respondents who had used cannabis during the year preceding the interview; and (2) to determine the differential severity of DSM-IV cannabis abuse and dependence criteria.
