Survey shows marijuana use disorder linked to substance use/mental disorders and disability.

Marijuana use disorder is common in the United States, is often associated with other substance use disorders, behavioral problems, and disability, and goes largely untreated, according to a new study conducted by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health. The analysis found that 2.5 percent of adults – nearly 6 million people – experienced marijuana use disorder in the past year, while 6.3 percent had met the diagnostic criteria for the disorder at some point in their lives. A report of the study, led by Bridget Grant, Ph.D., of the NIAAA Laboratory of Epidemiology and Biometry, appears online today in the American Journal of Psychiatry.

“The new analysis complements previous population-level studies by Dr. Grant’s group that show that marijuana use can lead to harmful consequences for individuals and society,” said George F. Koob, Ph.D., director of NIAAA.

In a recent report, Dr. Grant and her team found that the percentage of Americans who reported using marijuana in the past year more than doubled between 2001-2002 and 2012-2013, and the increase in marijuana use disorders during that time was nearly as large. The new study analyzed data about marijuana use that were collected in the 2012-2013 wave of NIAAA’s National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), the largest study ever conducted on the co-occurrence of alcohol use, drug use, and related psychiatric conditions.

The researchers interviewed more than 36,000 U.S. adults about alcohol use, drug use, and related psychiatric conditions. Notably, the current study applies diagnostic criteria for marijuana use disorder from Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to the NESARC data. 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 is rated as mild, moderate, or severe depending on the number of symptoms met.

Consistent with previous findings, the new data showed that marijuana use disorder is about twice as common among men than women, and that younger age groups are much more likely to experience the disorder than people age 45 and over. The risk for onset of the disorder was found to peak during late adolescence and among people in their early 20s, with remission occurring within 3 to 4 years. Also in keeping with previous findings, the new study found that past-year and lifetime marijuana use disorders were strongly and consistently associated with other substance use and mental health disorders. For more MUD always MUDdies the Brain