Please use this link to access this publication. Abstract Introduction Despite increases in the availability, potency, and consumption of cannabis, epidemiological data suggest decreases in the prevalence of cannabis use disorder (CUD) in some groups. Understanding mechanisms for these changes may help improve diagnostic tools for identifying disordered use. This analysis evaluates changes in CUD compared to a substance with comparably stable social and environmental context (alcohol use disorder [AUD]) as well as treatment engagement and need from 2002 to 2019. Methods Data were from the National Survey on Drug Use and Health. Outcomes included CUD and AUD symptoms, treatment engagement, and perceived need....