UM School of Medicine Review Highlights Rise in Psychiatric Disorders Linked to Increased Cannabis Use

Review Article Published in New England Journal of Medicine Finds 16 Million Americans Have Cannabis Use Disorder

The widespread use of cannabis (marijuana) and its increased potency are associated with a rise in cannabis-related psychiatric conditions, according to a new University of Maryland School of Medicine (UMSOM) review article that was recently published in the New England Journal of Medicine. It highlights the urgent need for doctors to screen for and treat patients who are experiencing symptoms of cannabis use disorder, which means they are experiencing significant problems from their use of the drug.  

Nearly one in five Americans ages 12 and older used cannabis in 2021, according to the article, and more than 16 million met the criteria for cannabis use disorder as outlined in the American Psychiatric Association’s Diagnostic and Statistical Manual of Health Disorders (DSM-5-TR). Young adults ages 18 to 25 are disproportionately affected. The review found more than 14 percent of those in this age group had cannabis use disorder.

“There is a lot of misinformation in the public sphere about cannabis and its effects on psychological health with many assuming that this drug is safe to use with no side effects,” said David A. Gorelick, MD, PhD, Professor of Psychiatry at UMSOM who wrote the review article. “It is important for physicians and the public to understand that cannabis can have addictive effects and to recognize signs and symptoms in order to get properly diagnosed and treated.”

Cannabis use disorder is defined as problematic marijuana use. Symptoms include craving the drug and failing to control its use despite experiencing negative side effects like problems at work or school. It is most prevalent in people who use cannabis more than four days a week. While the primary risk factors are the frequency and duration of cannabis use, having another substance use disorder or other psychiatric condition also increases the likelihood of the diagnosis.

“Almost 50 percent of people with cannabis use disorder have another psychiatric condition such as major depression, post-traumatic stress disorder, or generalized anxiety disorder,” said Dr. Gorelick. “It’s vital that patients seek the right psychiatric treatment to address their risk factors.”

Physical signs and symptoms of cannabis use disorder can range from yellowing of the fingertips to increased depression and anxiety while using cannabis. To be properly diagnosed by a clinician, however, patients must meet two or more criteria for cannabis use disorder as outlined by the DSM-5-TR. These include doing poorly at school or work or missing important family obligations due to cannabis use.  Experiencing withdrawal symptoms or cravings for cannabis are other symptoms.

Dr. Gorelick, who is also Editor-in-Chief of the Journal of Cannabis Research, conducted the extensive review to educate physicians on the array of health issues that may be associated with short-term and long-term cannabis use as a growing number of individuals use cannabis products. He also aimed to heighten public awareness around cannabis user disorder, both in terms of recognizing its symptoms and understanding treatment options.

The paper also highlighted other dangers of excessive cannabis use: Cannabis use accounts for 10 percent of all drug-related emergency room visits in the U.S. and is associated with a 30 to 40 percent increased risk of car accidents. In 2022, 18 to 25-year-olds accounted for the highest rate of cannabis-related emergency department visits.

“Approximately one in ten people who use cannabis will become addicted, and for those who start before age 18, the rate rises to one in six,” said Mark T. Gladwin, MD, the John Z. and Akiko K. Bowers Distinguished Professor and Dean, UMSOM, and Vice President for Medical Affairs, University of Maryland, Baltimore. “As use of this drug increases, we must delve deeply into basic research to understand the brain’s cannabinoid system. We must also design translational studies of therapies that target these brain mechanisms to help those with cannabis use disorder -- particularly young adults and pregnant women -- overcome their dependence on this drug.”

A key part of UMSOM’s mission is to drive innovation in the field of addiction medicine, and to learn more about neurological differences in the brain that make some people more susceptible to drug abuse and addiction.  As part of this mission, the school recently opened the Kahlert Institute for Addiction Medicine, which brings together leading addiction experts to collaborate on studying the brain mechanisms underlying addiction and to train a new generation of medical practitioners in the field of addiction medicine.

“There is still a lot we don’t understand about these conditions, including why some people experience cannabis-related disorders,” said Kahlert Institute Associate Director Asaf Keller, PhD, the Donald E. Wilson, MD, MACP Distinguished Professor and Chair of Neurobiology at UMSOM. “That is what we are trying to better understand through pre-clinical research studies. We are also working on developing treatments for cannabis -related disorders.”

There are currently seven recognized disorders related to cannabis use. Some include: cannabis-induced anxiety disorder, cannabis-induced psychotic disorder, cannabis-induced sleep disorder and cannabis-induced delirium, which manifests as hyperactivity, agitation and disorientation with hallucinations. Often, their symptoms can closely resemble those of their non-cannabis-related counterpart disorders.

To properly diagnosis patients for cannabis use disorder, the U.S. Preventive Services Task Force recommends that adolescents and adults be screened for cannabis use disorder (and other substance use disorders) in primary care settings as long as services for accurate diagnosis, treatment and appropriate care can be offered or referred. Screening is best done with a standalone or within a larger health questionnaire during a healthcare visit.  While the FDA has not approved any medication as effective for the treatment of cannabis use disorder, certain therapies can help those with cannabis use disorder manage symptoms and reduce or stop their cannabis use. These include: Cognitive Interactive Therapy (CBT) and Motivational Enhancement Therapy (MET), which help patients to manage thoughts and behaviors that trigger their use of cannabis and to better understand why they use cannabis. Adolescents may gain additional benefits from family-based treatment options.

Therapy is becoming more widely available through telehealth services, but the stigma around mental illness and addiction and the shortage of mental healthcare professionals still create barriers to treatment for many patients, Gorelick said.

About the University of Maryland School of Medicine

Now in its third century, the University of Maryland School of Medicine was chartered in 1807 as the first public medical school in the United States. It continues today as one of the fastest growing, top-tier biomedical research enterprises in the world -- with 46 academic departments, centers, institutes, and programs, and a faculty of more than 3,000 physicians, scientists, and allied health professionals, including members of the National Academy of Medicine and the National Academy of Sciences, and a distinguished two-time winner of the Albert E. Lasker Award in Medical Research. With an operating budget of more than $1.2 billion, the School of Medicine works closely in partnership with the University of Maryland Medical Center and Medical System to provide research-intensive, academic, and clinically based care for nearly 2 million patients each year. The School of Medicine has more than $500 million in extramural funding, with most of its academic departments highly ranked among all medical schools in the nation in research funding. As one of the seven professional schools that make up the University of Maryland, Baltimore campus, the School of Medicine has a total population of nearly 9,000 faculty and staff, including 2,500 students, trainees, residents, and fellows. The School of Medicine, which ranks as the 8th highest among public medical schools in research productivity (according to the Association of American Medical Colleges profile) is an innovator in translational medicine, with 606 active patents and 52 start-up companies. In the latest U.S. News & World Report ranking of the Best Medical Schools, published in 2023, the UM School of Medicine is ranked #10 among the 92 public medical schools in the U.S., and in the top 16 percent (#32) of all 192 public and private U.S. medical schools. The School of Medicine works locally, nationally, and globally, with research and treatment facilities in 36 countries around the world. Visit medschool.umaryland.edu