In NESARC-III, the odds for 12-month cannabis use disorders were higher among younger than older age groups, with striking differences between those age 18–29 and those ≥45 (ORs=6.5–9.7). While the prevalence of cannabis use disorder increased across all age groups between the 2001–2002 NESARC and the 2012–2013 NESARC-III, the age differential in DSM-5 cannabis use disorder in NESARC-III is considerably more pronounced than in the NESARC (17). The general increases suggest the operation of a period effect, while the sharply increased age differential suggests an additional cohort effect in the youngest adults. The general increase plus the sharp age differential in NESARC-III for DSM-5 cannabis use disorder are consistent with similar time trends among those favoring legalization of marijuana for recreational use (52). These trends all appear to reflect different manifestations of the increasingly accepting social attitudes towards marijuana use.
