Introduction:

Cannabis was legalized in California for recreational use through the passage of Proposition 64: The Adult Use Marijuana Act of 2016. This analysis from the Impact 64 study describes the cannabis use patterns of adults 21 years and older in California since the passage of Proposition 64.

Methods:

An online questionnaire addressing use of tetrahydrocannabinol-containing cannabis (including frequency, product(s), length, source, and purpose) was administered from December 2022 to February 2023. Of the initial 15,309 census-weighted participants, a subset of participants completed a detailed cannabis use questionnaire, including 4,020 people who currently use cannabis. Cannabis users were grouped by use frequency, and chi-squared analysis was utilized for descriptive analysis. Multinomial logistic regression was applied to assess significant variables associated with specific use patterns.

Results:

Of the initial sample of 15,208, 37% reported current cannabis use (with use in the past 3 months), 30% formerly used cannabis, and 33% were nonusers. Among current users, 38% reported very frequent use (multiple times a day), 33% frequent use (four times per week to daily), and 30% occasional use (three times per week or less). Compared with occasional users, very frequent users were more likely to be male (65%, odds ratio [OR] = 1.8, p < 0.001), less educated (OR = 1.7, p < 0.001), and have lower incomes (under 50K vs 100K, OR = 2.3, p < 0.001). Most users reported multiple cannabis products, mainly flower inhalation (80%), vaping (66%), and edibles (61%), primarily sourced from dispensaries (77%), which the majority (94%) perceived as licensed. Of all current users, most used cannabis at home (93%) or for entertainment (75%), with many reporting use during creative activities (45%), with alcohol (36%) and/or with cigarettes (24%). Positive impacts were reported in mental (82%), emotional (81%), and physical (62%) health. The internet (51%) and friends/family (50%) were the main sources of information. Most current users felt comfortable discussing cannabis with their primary doctor (78%), although only 66% of primary doctors knew about recreational use.

Discussion:

There is a high prevalence of daily cannabis use among adult Californians, with most users obtaining products from perceived licensed dispensaries or delivery services. While most users feel comfortable discussing cannabis use with physicians, they primarily obtain information from other sources, highlighting the need to bridge this information gap.