Use of marijuana exclusively for medical purposes.

Objectives: To characterize the socio-demographic characteristics, medical conditions, and psychiatric comorbidities of users of marijuana for medical and non-medical purposes.
Methods: Data were from the National Epidemiological Survey on Alcohol and Related Conditions III, a US nationally representative in-person interview of 36,309 adults age ≥18 years in 2012-2013.
Results: In relation to non-medical only users (n = 3339), combined (n = 362) and medical only (n = 82) users had higher prevalence of every medical condition examined. As compared to the combined use group, those using marijuana only for medical purposes were much less likely to have anxiety, alcohol, or non-medical prescription opioid use disorders.
Conclusions: Medical-only users appear to use it for evidence-based medical reasons and have lower prevalence of substance use disorder than other marijuana users. Nonetheless, because most medical marijuana users also use non-medically, screening for psychiatric disorders and prevention efforts for cannabis use disorder should be implemented when authorizing medical marijuana.
(Copyright © 2018. Published by Elsevier B.V.)