NEW YORK, NY (March 16, 2016)—A new study published in the American Journal of Psychiatry has found that number of Americans who reported using marijuana over a one-year period more than doubled between 2002 and 2013, with nearly as large an increase in marijuana use disorders during that time period. The study also revealed that 2.5 percent of adults—nearly 6 million people—experienced marijuana use disorder in the past year, while 6.3 percent met the diagnostic criteria for the disorder at some point in their lives.
The researchers also found that marijuana use disorder is often associated with other substance use disorders, behavioral problems, and disability, and goes largely untreated.
The collaborative study was carried out by scientists at Columbia University’s Mailman School of Public Health (MSPH), Columbia University Medical Center (CUMC), and the National Institute on Alcohol Abuse and Alcoholism (NIAAA), which is part of the National Institutes of Health.
The data were collected in the 2012-2013 wave of NIAAA’s National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), the largest study of the co-occurrence of alcohol use, drug use, and related psychiatric conditions. For this study, over 36,000 adults were interviewed about alcohol and drug use and related psychiatric conditions. The data showed that marijuana use disorder is about twice as common in men than women, particularly in those younger than age 45 and those at the lowest income levels.
This is the first national survey to use diagnostic criteria from Diagnostic and Statistical Manual of Mental Disorders (DSM-5). In DSM-5, marijuana dependence and abuse are combined into a single disorder. To be diagnosed with the disorder, individuals must meet at least two of 11 symptoms that assess craving, withdrawal, lack of control, and negative effects on personal and professional responsibilities. Severity of the disorder was rated as mild, moderate, or severe depending on the number of symptoms. As the severity of marijuana use disorder increased, so did associated disability levels and frequency of marijuana use.
Deborah Hasin, PhD, lead author and professor of epidemiology in the Department of Psychiatry at CUMC with a joint appointment in the Department of Epidemiology in the MSPH, participated in the working group responsible for making the changes in DSM-5 substance use diagnostic criteria, including marijuana use disorders. In a study published last year, Dr. Hasin reported that three out of 10 marijuana users experienced marijuana abuse or dependence in 2012-13.
“An increasing number of American adults do not perceive marijuana use as harmful,” said Hasin. “While some can use marijuana without harms, other users do experience negative consequences, which can include mental and physical problems, and impaired functioning. This paper helps provide information about some of those risks.”
The researchers found that only 7 percent of people diagnosed with marijuana use disorder during the past year received any marijuana-specific treatment, and just 14 percent of people with lifetime marijuana use disorder received treatment.
“The new analysis complements previous population-level studies conducted by the National Institute on Alcohol Abuse and Alcoholism that show marijuana use can lead to harmful consequences for individuals and society,” said George F. Koob, PhD, director of NIAAA.
“These findings demonstrate that people with marijuana use disorder are vulnerable to other mental health disorders,” said Nora D. Volkow, MD, director of the National Institute of Drug Abuse (NIDA), which contributed funding to the study. “The study emphasizes the need for such individuals to receive help through evidence-based treatments that address these co-occurring conditions.”
The study authors noted the urgency of identifying and implementing effective prevention and treatment for marijuana use disorder and call for more research to understand the combined effects of marijuana and alcohol. “We feel strongly that more public education about the dangers associated with marijuana use is imperative,” stated Hasin. “This is especially critical since we are learning more about public beliefs that marijuana use is harmless.”
“Prevalence and Correlates of DSM-5 Cannabis Use Disorder, 2012-2013: Findings from the National Epidemiologic Survey on Alcohol and Related Conditions – III,” published online March 4, 2016 in the American Journal of Psychiatry. Authors are Deborah S. Hasin (CUMC, MSPH and New York State Psychiatric Institute), Bradley T. Kerridge (MSPH), Tulshi D. Saha, Risë B. Goldstein, S. Patricia Chou, Haitao Zhang, Jeesun Jung, Roger P. Pickering, W. June Ruan, Sharon M. Smith, Boji Huang, MD, and Bridget F. Grant (NIAAA).
The authors report no conflicts of interest.
Columbia Psychiatry holds the top ranking among the psychiatry departments in the nation and has contributed greatly to the understanding and treatment of brain disorders. Co-located at the New York State Psychiatric Institute on the NewYork-Presbyterian Hospital/Columbia University Medical Center campus in Washington Heights, the department enjoys a rich and productive collaborative relationship with physicians in various disciplines at Columbia University’s College of Physician’s and Surgeons. Columbia Psychiatry is home to distinguished clinicians and researchers noted for their clinical and research advances in the diagnosis and treatment of depression, suicide, schizophrenia, bipolar and anxiety disorders, eating disorders, substance use disorders, and childhood psychiatric disorders.
About Columbia University’s Mailman School of Public Health
Founded in 1922, Columbia University’s 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 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 Mailman School is also home to numerous world-renowned research centers including ICAP (formerly the International Center for AIDS Care and Treatment Programs) and the Center for Infection and Immunity. For more information, please visit www.mailman.columbia.edu
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