Among youth and emerging adults in the US, prevalence of cannabis use disorder appears to increase with time since initiation of use, according to a recent study. This increase appears to be steeper for youth than emerging adults. Researchers utilized repeated cross‐sectional survey data from the 2015‐2017 National Surveys on Drug Use and Health (NSDUH). Participants included 101,000 NSDUH participants aged 12‐25 years. They found:

• Among youth, the lifetime prevalence of cannabis use was 15.3%.
• Among emerging adults, the lifetime prevalence of cannabis use was 52.4%.
• The adjusted 12‐month prevalence of cannabis use disorder among youth with lifetime cannabis use was 10.9% in the first year after starting cannabis use, 15.3% in the second year, 17.7% in the third year, and 20.6% in the fourth year and beyond, which was consistently higher after the first year.
• The adjusted 12‐month prevalence of cannabis use disorder among emerging adults with lifetime use ranged from 5.6% in the first year after starting cannabis use, 7.7% in the second year, 9.1% in the third year, to 10.5% in the fourth year and beyond, which was consistently higher after the first year.