October 30, 2019 -- The prevalence of cannabis use disorder decreased in 2002 to 2016 among frequent users, according to a new study conducted at Columbia University Mailman School of Public Health. Changes in social attitudes and the traits of frequent users may explain the decline, according to researchers. This is one of the first studies to examine the general health profile of people using cannabis daily or almost daily and the trends in the prevalence of cannabis use disorder in this population. The findings are online in the journal Drug and Alcohol Dependence.
"Contrary to expectations, the frequency of cannabis use disorder among people reporting daily/almost daily use decreased significantly between 2002-2016, said Silvia Martins, MD, PhD, associate professor of Epidemiology at Columbia Mailman School. "The findings contradict the predominating hypothesis that the prevalence of DSM-IV CUD would be stable, or increase, among those using with this regularity."
Data from the National Survey on Drug Use and Health for 2002-2016 included 22,651 individuals using cannabis 300+ days in the past year. Cannabis use disorder was defined using DSM-IV criteria for cannabis abuse and/or dependence. Age categories included: 12-17, 18-25, and 26?and older.
From 2002-2016, the prevalence of cannabis use disorder among people reporting daily or almost daily use decreased across all age groups -- by 27 percent in adolescents, by 30 percent in ages 18-25, and by 37.5 percent for those age 26 and older.
"There could be several reasons behind these declining rates," noted Martins, who is also director, Substance Use Epidemiology Unit at Columbia. "First, the new national cannabis policy environment, with 33 states legalizing medical use and 10 states allowing recreational use of cannabis may have played a role in reducing stigma and perceptions of risk associated with cannabis use. "Secondly, increasing legalization may also be associated with changes in social attitudes resulting in fewer conflicts with relatives and friends around cannabis use."
For all age groups, there was no evidence of any significant reductions in the perceived need for mental health treatment among individuals using cannabis regularly (daily/near daily), or the prevalence of health problems as indicated by doctors.
The researchers also did not find evidence of significant reductions in prevalences of past-year health problems when examining health clusters separately including mental health, respiratory, digestive, cardiovascular, and infectious diseases health problems.
In contrast, there were significant decreases in self-reported driving under the influence of illegal drugs including alcohol across all age groups, ranging from a 26 percent, 29 percent and 38 percent change in adolescents, those 18-24 and age 26 and older, respectively.
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The study was supported by the National Institute on Drug Abuse (grants K01DA045224 and R01DA 037866).
Co-authors are: Julian Santaella-Tenorio, corresponding author; Natalie S. Levy, Luis E. Segura, and Pia M.Mauro, Department of Epidemiology, Columbia Mailman School of Public Health.
Columbia University Mailman School of Public Health
Founded in 1922, the Columbia University Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Columbia Mailman School is the third largest recipient of NIH grants among schools of public health. Its over 450 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change & health, and public health preparedness. It is a leader in public health education with over 1,300 graduate students from more than 40 nations pursuing a variety of master's and doctoral degree programs. The Columbia Mailman School is also home to numerous world-renowned research centers, including ICAP and the Center for Infection and Immunity. For more information, please visit http://www.mailman.columbia.edu.
Journal
Drug and Alcohol Dependence