(11) Associations between Gender and Prevalence of Daily Cannabis Use from 2008-2019

Background & Introduction: Cannabis use is common, and the prevalence of cannabis use has increased over the past two decades.¹ For example, among adults in the United States, the past-year prevalence of cannabis use increased from 10.4% to 15.3% from 2002-2017, and daily or near daily use (defined as ≥300 days per year) increased from 1.9% to 4.2%.² There is a gender gap in substance use where there is a greater prevalence in men compared to women.³ Prevalence of past-year cannabis use increased more for men (+4.0%) than for women (+2.7%) from 2002-2014.⁴ To our knowledge, there has not been investigation into the change in daily cannabis use by gender over time. In the current study, we examined the association between gender and daily cannabis use, and how this association has changed over time.

Methods: In this cross-sectional study, we analyzed data from respondents aged 18 and older who completed the National Survey on Drug Use and Health (NSDUH) between the years 2008 and 2019. Our primary outcomes were prevalence and likelihood of daily cannabis use. We defined daily cannabis use as having used cannabis ≥300 days in the past year. Our main variables of interest were (1) year, which we examined over the time period from 2008-2019, (2) gender, which NSDUH defined as male or female during our time period of interest, and (3) the interaction between these variables. Both year and gender were treated as categorical variables. We used logistic regression to model the likelihood of daily cannabis use as function of our variables of interest while adjusting for demographic variables including race and ethnicity, co-occurring psychiatric illness, other substance use, and cannabis use disorder. Analyses were weighted to account for NSDUH’s complex survey design.

Results: Prevalence of daily cannabis use among adults more than doubled from 1.68% in 2008 to 3.90% in 2019. Prevalence of daily cannabis use was higher among men than women for every year measured, but the change in prevalence of daily cannabis use from 2008 to 2019 increased more among women than men: there was a 193% increase among men (from 2.60% in 2008 to 5.03% in 2019), and a 347% increase among women (from 0.82% in 2008 to 2.85% in 2019). The interaction between gender and year was statistically significant for years 2015-2019 (AOR 1.13, 95% CI 1.07-1.19, p< 0.0001) indicating the rate of increase in daily cannabis use per year was significantly higher for women than for men during this time. We observed an association between race and ethnicity and likelihood of daily cannabis use from 2008 to 2019, such that Black and Native American persons were more likely to use cannabis daily compared to White persons (AOR 1.33, 95% CI 1.19-1.47, p< 0.0001 for Black vs. White comparison; AOR 1.26, 95% CI 1.06-1.50, p< 0.0001 for Native American vs. White comparison).

Conclusion & Discussion: The prevalence of daily cannabis use among U.S. adults is increasing in both men and women, and the rate of increase is higher in women compared to men since 2015. As frequent cannabis use is associated with risks of psychosis and other adverse outcomes,¹ and given that women have more severe adverse medical, psychiatric, and functional consequences associated with substance use compared to men,³ our results point to the need to understand whether these changing patterns of use are associated with negative health outcomes. In addition, we found that Black and Native American races and ethnicities have a disparately increased likelihood of daily cannabis use compared to White persons. This places these already vulnerable and underserved populations at a potentially increased risk from cannabis use. Further research is needed to explore the risks associated with daily use, especially in women and racial and ethnic minoritized persons, as patterns of cannabis use change and more people use daily.

References:
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2. Compton WM, Han B, Jones CM, Blanco C. Cannabis use disorders among adults in the United States during a time of increasing use of cannabis. Drug Alcohol Depend. 2019 Nov 1;204:107468. doi: 10.1016/j.drugalcdep.2019.05.008. Epub 2019 Sep 12. PMID: 31586809; PMCID: PMC7028308.

3. McHugh RK, Votaw VR, Sugarman DE, Greenfield SF. Sex and gender differences in substance use disorders. Clin Psychol Rev. 2018 Dec;66:12-23. doi: 10.1016/j.cpr.2017.10.012. Epub 2017 Nov 10. PMID: 29174306; PMCID: PMC5945349

4. Carliner H, Mauro PM, Brown QL, Shmulewitz D, Rahim-Juwel R, Sarvet AL, Wall MM, Martins SS, Carliner G, Hasin DS. The widening gender gap in marijuana use prevalence in the U.S. during a period of economic change, 2002-2014. Drug Alcohol Depend. 2017 Jan 1;170:51-58. doi: 10.1016/j.drugalcdep.2016.10.042. Epub 2016 Nov 11. PMID: 27875801; PMCID: PMC5321672.