People have been using marijuana as medicine since ancient times. The verdict is still out on whether it’s healthy, even in light of the drug now being legal for medicinal use in 23 states, four of which also permit its recreational use. Although there’s a lot of conflicting evidence regarding the effects cannabis has on health — especially mental health — many of its consumers believe it’s relatively harmless. Scientists from Columbia University now say these opinions may keep those dependent on the drug from seeking treatment.

Marijuana Use Disorder

The study, published in the American Journal of Psychiatry, found that six million adults have experienced marijuana use disorder in the past year, but only 7 percent received any marijuana-specific treatment. Nearly 15 million adults in the United States said they had met the diagnostic criteria for marijuana abuse or dependence at some point in their lives, but only 13 percent sought professional treatment.

When diagnosing marijuana use disorder in a patient, physicians are required to identify two of at least 11 symptoms that assess craving, withdrawal, lack of control, and whether the drug has had any negative effects on personal and professional responsibilities within 12 months. Depending on the number of symptoms, dependency can be rated as mild, moderate or severe. Symptoms of this disorder include cravings, disruption in functioning, and developing withdrawal symptoms, such as the inability to sleep, or becoming restless, angry, or depressed within a week of stopping heavy use.

"An increasing number of American adults do not perceive marijuana use as harmful," Dr. Deborah Hasin, lead author of the study, said in a statement. "While some can use marijuana without harms, other users do experience negative consequences, which can include mental and physical problems, and impaired functioning.”

Led by Hasin, researchers reviewed data from more than 36,000 U.S. adults who participated in the National Epidemiologic Survey on Alcohol and Related Conditions. They found that marijuana dependence is nearly twice as common among men than women, and that young adults between the ages of 18 and 24 years old are much more likely to abuse marijuana than people 45 and older. People with low income levels had the highest risk for developing the disorder.

Marijuana use disorder was also strongly and consistently associated with other substance and mental disorders, suggesting that despite the softening of social attitudes toward the drug and its increased use, “persons with cannabis use disorder continue to be vulnerable to other common mental disorders,” the study authors wrote. Researchers also found that the disorder is linked to other substance use disorders, confirming results from a previous study, as well as behavioral problems, and disability. However, despite these health risks, marijuana use disorders go largely untreated.

"These findings demonstrate that people with marijuana use disorder are vulnerable to other mental health disorders," said Dr. Nora D. Volkow, director of the National Institute of Drug Abuse, which helped fund the study. "The study emphasizes the need for such individuals to receive help through evidence-based treatments that address these co-occurring conditions."

Marijuana’s Effect On Mental Health

With more states legalizing marijuana for medicinal and recreational use, and so much uncertainty surrounding the drug, many people are concerned about its health effects.

While some studies have shown that the drug may benefit those suffering from mental health disorders, like stress, anxiety, and post-traumatic stress disorder (PTSD), others have suggested that the substance is linked to cognitive decline and psychosis, a serious mental disorder marked by impaired thinking and emotions.

"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."

While more research is needed to examine marijuana’s long-term impact on mental health, researchers say cannabis use disorder is a serious issue and can be a disabling and disruptive disorder if left untreated. “The study highlights the need to educate the public, professionals, and policy makers about the seriousness of cannabis use disorder and the need for public health efforts to destigmatize and encourage seeking help for cannabis use disorder among individuals who cannot reduce their use of marijuana on their own, despite substantial harm to themselves and others,” the authors wrote.

Source: Hsain D, Kerridge B, Saha T, et al. Prevalence and Correlates of DSM-5 Cannabis use Disorder, 2012-2013: Findings from the National Epidemiologic Survey on Alcohol and Related Conditions-III. American Journal of Psychiatry. 2016.