Although the findings of this study strongly support the addition of one cannabis use criterion, i.e., consumption of at least one joint at least once a week during the past year, as a new DSM-V cannabis use disorder criterion, cannabis use can be measured in a variety of ways, by frequency only, by quantity only, or by quantity and frequency. The need for future research to conduct empirical tests of alternative definitions of cannabis use as candidate DSM-V criteria, which this study was unable to accomplish, is critical. Any alternative criterion, however, must demonstrate, at minimum, the informational and discriminatory power associated with consumption of at least one joint at least once a week during the past year, as well as the ability to tap the lower end of the severity continuum.
