Trends in cannabis use among adults with children in the home in the United States, 2004-2017: impact of state-level legalization for recreational and medical use

Abstract

Background and aims: Cannabis use among parents may be increasing with legalization, but perception of associated risk has declined. The study investigated the association between cannabis legalization and cannabis use among adults with children in the home over time in the United States (US).

Design: A difference-in-difference approach was applied to public and restricted-use data from the 2004-2017 National Survey on Drug Use and Health (NSDUH), an annual cross-sectional survey.

Setting: A representative sample of the United States.

Participants/cases: Respondents ages 18+ with children living in the home drawn from the NSDUH (n = 287,624), which is administered to non-institutionalized civilians in the 50 states and District of Columbia.

Measurements: Exposures were year and state-level cannabis policy in state of residence annually. Outcomes were past-30-day cannabis use and daily cannabis use. Sociodemographic variables included age, gender, marital status, annual family income, race/ethnicity, educational attainment, and strength of state-level tobacco control.

Findings: In 2017, past-month cannabis use (11.9%, 9.3%, and 6.1%) and daily cannabis use (4.2%, 3.2%, and 2.3%) were more common in states with recreational marijuana laws (RML), followed by states with medical marijuana laws (MML) and without legal cannabis use, respectively. RML and MML were associated with significantly higher prevalence of past-month cannabis use (adjusted odds ratio [AOR] = 1.28, 95% confidence interval [CI] = 1.12-1.46; AOR = 1.12, 95% CI = 1.03-1.22) and daily cannabis use (AOR = 1.25, 95% CI = 1.03-1.51; AOR = 1.16, 95% CI = 1.02-1.32), respectively. The impact of MML was particularly salient among adults ages 50+ and the highest income and education subgroups.

Conclusions: Among adults with children living in the home, cannabis use appears to be more common in US states with legalized cannabis use compared with states with no legal cannabis use. Recreational legalization appears to increase use among adults with children in the home broadly across nearly all sociodemographic groups, whereas the effect of legalization for medical use is heterogeneous by age and socioeconomic status.

Keywords: Cannabis; NSDUH; epidemiology; legalization; marijuana; substance use.