Older-adult marijuana users and ex-users: Comparisons of sociodemographic characteristics and mental and substance use disorders.

BACKGROUND: The increasing numbers of older-adult marijuana users call for better understanding of their mental and substance use disorders (MSUDs).

METHODS: Data came from the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-III; N=14,715 respondents aged 50 +). Multinomial logistic regression analysis was used to compare never users, past-year users, and ex-users on past-year and lifetime MSUDs. Binary logistic regression analysis was used to examine the association of marijuana use patterns in the past year and during the peak use period with lifetime MSUDs.

RESULTS: Of the 50+ age group, 3.9% were past-year marijuana users and 21.7% were ex-users. Past-year users did not differ from ex-users with respect to past-year or lifetime mental disorders, but they had higher risks of past-year other drug use (RRR=2.73, 95% CI=1.63-4.55), alcohol use (RRR=2.30, 95% CI=1.78-2.98), and tobacco/nicotine use (RRR=1.87, 95% CI=1.50-2.34) disorders. Among past-year users, the number of joints smoked during the peak use period (OR=1.14, 95% CI=1.04-1.26) and past-year use frequency (OR=2.20, 95% CI=1.37-3.52) were significantly associated with greater odds of lifetime marijuana/other drug use disorder. Among ex-users, the number of joints smoked during the peak use period was significantly associated with any mental (OR=1.05, 95% CI=1.01-1.09) and marijuana and/or other drug use (OR=1.13, 95% CI=1.06-1.21) disorder.

CONCLUSIONS: Older-adult past-year marijuana users and ex-users had similarly high risks for past-year and lifetime mental disorders, but past-year users had a higher risk for substance use disorders. Health/mental health providers should be concerned about the increasing number of older-adult long-term marijuana users with MSUDs.