Embargoed for Release: 11 a.m. ET Monday, December 19, 2016
To place an electronic embedded link to these studies in your story These links will be live at the embargo time: http://jamanetwork.com/journals/jama/fullarticle/10.1001/jama.2016.17383
Two studies published online by JAMA examine trends in marijuana use among pregnant and nonpregnant women of reproductive age, and use for medical purposes among adults in the United States.
In one study, Deborah S. Hasin, Ph.D., Qiana L. Brown, Ph.D., M.P.H., L.C.S.W., of Columbia University, New York, and colleagues used data from women ages 18 through 44 years from the annual National Survey on Drug Use and Health from 2002 through 2014 to determine whether marijuana use has changed over time among pregnant and nonpregnant reproductive-aged women.
Between 2001 and 2013, marijuana use among U.S. adults more than doubled, many states legalized marijuana use, and attitudes toward marijuana became more permissive. In aggregated 2007-2012 data, 3.9 percent of pregnant women and 7.6 percent of nonpregnant reproductive-aged women reported past-month marijuana use. Although the evidence is mixed, human and animal studies suggest that prenatal marijuana exposure may be associated with poor offspring outcomes (e.g., low birth weight, impaired neurodevelopment). The American College of Obstetricians and Gynecologists recommends that pregnant women and women contemplating pregnancy be screened for and discouraged from using marijuana and other substances.
Of the 200,510 women analyzed, 29.5 percent were ages 18 through 25 years and 70.5 percent were ages 26 through 44 years; 5.3 percent (n = 10,587) were pregnant. Among all pregnant women, the prevalence of past-month marijuana use increased from 2.4 percent in 2002 to 3.9 percent in 2014, an increase of 62 percent. The prevalence of past-month marijuana use was highest among those ages 18 to 25 years, reaching 7.5 percent in 2014, significantly higher than among those ages 26 to 44 years (2.1 percent). However, increases over time did not differ by age. Past-year use was higher overall, reaching 11.6 percent in 2014, with similar trends over time. In nonpregnant women, prevalences of past-month use (2014: 9.3 percent) and past-year use (2014: 16 percent) were higher overall, with similar trends over time. Increases over time in past-month marijuana use did not differ by pregnancy status.
“These results offer an important step toward understanding trends in marijuana use among women of reproductive age. Although the prevalence of past-month use among pregnant women (3.85 percent) is not high, the increases over time and potential adverse consequences of prenatal marijuana exposure suggest further monitoring and research are warranted. To ensure optimal maternal and child health, practitioners should screen and counsel pregnant women and women contemplating pregnancy about prenatal marijuana use,” the authors write.
(doi:10.1001/jama.2016.17383; the study is available pre-embargo at the For the Media website)
Editor’s Note: This work was supported by grants from the National Institute on Drug Abuse and the New York State Psychiatric Institute. All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
In another study, Wilson M. Compton, M.D., M.P.E., of the National Institute on Drug Abuse, Bethesda, Md., and colleagues examined differences between medical and nonmedical marijuana users across all U.S. states.
By 2014, 23 states and the District of Columbia had legalized medical marijuana use, suggesting a need for information about national rates of marijuana use for medical purposes. Although 17 percent of past-year marijuana users reported use for medical purposes in states with medical marijuana legalization, physicians might recommend medical marijuana use to patients regardless of their residing states.
For this study, the researchers used data from adults 18 years and older who participated in the 2013-2014 National Survey on Drug Use and Health, which provides representative data on marijuana and other substance use among the U.S. population. Based on 96,100 respondents, 13 percent of U.S. adults had past-year marijuana use (nonmedical use only, 12 percent, medical use only, 0.8 percent, combined use, 0.5 percent). Among past-year adult marijuana users, 90 percent used nonmedically only, 6.2 percent used medically only, and 3.6 percent used medically and nonmedically. Of medical marijuana users, 79 percent resided in states where medical marijuana was legal, and 21 percent resided in other states.
“Using nationally representative data, 9.8 percent of adult marijuana users in the United States reported use for medical purposes. Although the prevalence of medical use was higher in states that had legalized medical marijuana, 21.2 percent of medical marijuana users resided in states that had not, suggesting physicians might recommend medical marijuana use regardless of legalization,” the authors write.
“Similarities in correlates of medical and nonmedical users, especially co-occurrence with psychiatric conditions and other substance use, suggest that some marijuana users may access medical marijuana without medical need. However, medical-only marijuana users differed from nonmedical-only users in ways that are consistent with use to address medical problems.”
(doi:10.1001/jama.2016.18900; the study is available pre-embargo at the For the Media website)
Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
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