Why do Americans use marijuana?

Marijuana is the most commonly used illicit drug in the United States; yet, little is known about why adults use it. We examined the prevalence of past-month marijuana use by users' reasons for use-medical, recreational, and both-and identified correlates of each group.

Data from 20 states, which participated in the 2017-2019 Behavioral Risk Factor Surveillance System and fielded the marijuana use module, and multinomial logistic regression analysis were used to identify risk factors for past-month marijuana use by reason for use. User profiles were developed to illustrate how states' policy environments influenced reported reasons for use.

The average predicted probabilities of past-month marijuana use for medical, recreational, and both reasons were 28.6 %, 38.2 %, and 33.1 %, respectively. Age, gender, marital and employment status, income, mode and frequency of administration, and health status were associated with reasons for use. The reasons that young adult males who were infrequent marijuana users and binge drinkers gave for their marijuana use varied by state policy environment-in legal states, the average predicted probabilities were 5.3 % lower for recreational reasons and 5.0 % higher for both reasons. Reported reasons for past-month marijuana use did not significantly differ by state policy environment among daily users who were older women in poor mental and physical health.

Significant differences existed in the characteristics of past-month marijuana users by reasons for use. Our estimates can serve as a baseline against which post-legalization marijuana users' reasons for use can be compared as state policy environments shift.