Cannabis use disorder among people using cannabis daily/almost daily in the United States, 2002–2016

•The prevalence of cannabis use disorder decreased in frequent cannabis users.•Endorsement of cannabis abuse items decreased in adolescents and young adults.•Endorsement of cannabis dependence items decreased mainly in young adults.•Changes in social attitudes and frequent users’ features may explain findings. Cannabis use disorder (CUD) prevalence among people reporting past-year cannabis use declined from 2002–2016. We examined whether similar reductions in CUD were observed among people reporting daily/almost daily cannabis use. We expected that CUD prevalence among people reporting daily/almost daily use would not decrease. We used 2002–2016 National Survey on Drug Use and Health (NSDUH) data, including 22,651 individuals using cannabis 300+ days in the past year. CUD was defined using DSM-IV criteria for cannabis abuse and/or dependence. Age categories included: 12–17, 18–25, and 26 + . Annual prevalence of CUD, cannabis dependence, cannabis abuse, and each individual abuse/dependence items accounted for the complex survey design. Differences in trends over time were examined by age group. From 2002–2016, the prevalence of CUD among people reporting daily/almost daily cannabis use decreased by 26.8% in adolescents, by 29.7% in ages 18–25, and by 37.5% in ages 26 + . Prevalence of DSM-IV cannabis dependence decreased significantly among adolescents (-43.9%) and young adults (-26.8%) but remained stable in adults 26 + . Reductions in most dependence items were observed in young adults, with less consistent patterns in adolescents and adults 26 + . Prevalence of DSM-IV cannabis abuse decreased overall and for each abuse item across all age groups. Contrary to expectations, CUD prevalence decreased significantly across all ages reporting daily/almost daily cannabis use between 2002–2016. Cannabis dependence prevalence decreased for adolescents and young adults and was stable only among adults ages 26+ reporting daily/almost daily cannabis use. Potential drivers of this decrease should be further explored.