Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Mar;113(3):473-481.
doi: 10.1111/add.14031. Epub 2017 Oct 11.

Trends and age, period and cohort effects for marijuana use prevalence in the 1984-2015 US National Alcohol Surveys

William C Kerr  1 , Camillia Lui  1 , Yu Ye  1
Affiliations

Trends and age, period and cohort effects for marijuana use prevalence in the 1984-2015 US National Alcohol Surveys

William C Kerr et al. Addiction. 2018 Mar.

Abstract

Background and aims: Epidemiological trends show marijuana use in the United States to have increased in recent years. Previous research has identified cohort effects as contributing to the rising prevalence, in particular birth cohorts born after 1945. However, given recent policy efforts to regulate marijuana use at the state level, period effects could also play a contributory role. This study aimed to examine whether cohort or period effects play a larger role in explaining trends in marijuana use.

Design: Using data from seven National Alcohol Surveys, we estimated age-period-cohort decomposition models for marijuana use, controlling for socio-demographic measures.

Setting: United States.

Participants: US general population aged 18 and older from 1984 to 2015.

Measurements: Any past-year marijuana use.

Findings: Results indicated that period effects were the main driver of rising marijuana use prevalence. Models including indicators of medical and recreational marijuana policies did not find any significant positive impacts.

Conclusions: The steep rise in marijuana use in the United States since 2005 occurred across the population and is attributable to general period effects not linked specifically to the liberalization of marijuana policies in some states.

Keywords: Age; age-period-cohort; legalization; marijuana; marijuana policy; trends.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest and financial disclosure: no conflicts to disclose

Figures

Figure 1
Figure 1
Age, period and cohort effects for women and men displayed as odds ratios (OR) from logistic regression models of any marijuana use from 7 National Alcohol Surveys. Reference groups are the 41–50 age group, the 2015 survey and the 1956–1960 birth cohort. Dotted lines represent the estimated 95% confidence intervals. Male age effects are estimated from the age-constraint model, and thus no confidence intervals are not presented.
See this image and copyright information in PMC

Comment in

References

    1. Wu L-T, Zhu H, Swartz M. Trends in cannabis use disorders among racial/ethnic population groups in the United States. Drug Alcohol Depend. 2016;165:181–90. - PMC - PubMed
    1. Lanza ST, Vasilenko SA, Dziak JJ, Butera NM. Trends among U.S. high school seniors in recent marijuana use and associations with other substances: 1976–2013. J Adolesc Health. 2015;57(2):198–204. - PMC - PubMed
    1. Han BH, Sherman S, Mauro PM, Martins SS, Rotenberg J, Palamar JJ. Demographic trends among older cannabis users in the United States, 2006–2013. Addiction. 2017;112(3):516–25. - PMC - PubMed
    1. Kerr WC, Greenfield TK, Bond J, Ye Y, Rehm J. Age-period-cohort influences on trends in past year marijuana use in the U.S. from the 1984, 1990, 1995, and 2000 National Alcohol Surveys. Drug Alcohol Depend. 2007;86(2–3):132–8. - PubMed
    1. Miech R, Koester S. Trends in U.S., past-year marijuana use from 1985–2009: an age-period-cohort analysis. Drug Alcohol Depend. 2012;124:259–67. - PMC - PubMed

Publication types