Cannabis Use Disorder Rising, Especially Among Mentally Ill

A great deal of excitement continues to be generated by the legalization of nonmedical cannabis use, also known as recreational or social use. Thankfully, cannabis users no longer need to fear arrest and harsh incarceration. Past criminal records for mere possession are gradually being expunged. Products tested for purity have become more available. And, despite their lack of testing for safety, higher-THC products have also become available through vaping and concentrates marketed by an industry bent on normalizing cannabis use. As legalization and commercialization have become more accepted, the public’s perception of cannabis as harmless has grown.

Much of this excitement is built on a foundation of ignoring and outright denying several inconvenient truths. I understand the tendency to suppress awareness of the potential downsides to one’s pleasures. For example, almost everyone who drinks alcohol recreationally or grabs a fast-food meal avoids thinking of the negative consequences of dulling their mind or clogging their arteries. In truth, it would be wonderful for cannabis users if science found that people could use cannabis with no concern for side effects. How sweet it would be if cannabis use were proven to be free of any physical, cognitive, or emotional consequences—a myth indulged by many cannabis users.

Most people can occasionally use moderate amounts of cannabis or alcohol without concern for more than avoiding driving while under the influence. “Most people," however, does not include those with a history of addictive disease or mental illness, those who are pregnant, and, most especially, children and adolescents. If you are an adult who does not fall into one of these higher-risk categories, moderate amount and frequency of use is generally safe.

Canadian researchers have clearly shown that, while the legalization of recreational cannabis did not cause increased use, commercialization increases sales. (For more, see Pot Commercialization Has Increased Hospitalizations.) Now a new study¹using data from the Veterans Administration (VA), the largest integrated healthcare system in the U.S., has analyzed trends in the prevalence of Cannabis Use Disorder (CUD) between 2005 and 2019. The number of patient records analyzed rose from 4.3 to 5.6 million over the period studied. During that time, the rate of Cannabis Use Disorder among veterans, diagnosed by evidence of social and occupational impairments as well as overt addiction, has more than doubled, a rate disproportionately higher than the increase in the general public. Given the higher rate of psychiatric disorders among veterans compared to the general public, the confluence of CUD with psychiatric comorbidity is of special interest.

The study looked at trends within three age groups: under 35; 35-64; and 65 and up. In addition, researchers analyzed trends in CUD among patients with diagnoses of depression, anxiety, posttraumatic stress, bipolar disorder, and psychotic spectrum disorders, without regard to whether these comorbidities predated or followed a diagnosis of CUD. A higher rate of CUD was found in patients with psychiatric comorbidities than in those without comorbidities, and the highest rates were among patients with bipolar and psychotic spectrum disorders. Patients 65 and older had the highest rate of CUD and comorbidity over the last five years.

This study reinforces what we have already known: Cannabis poses the greatest risk, and almost certainly does the greatest harm, to the most vulnerable. My decades of psychiatric practice brought me into contact with people’s resistance to starting psychiatric medication. This resistance comes from both the difficulty of acknowledging that a mental-health problem is severe enough to warrant medication as well as a distrust of Western medicine. Many patients hunt for alternatives, and the cannabis industry’s marketing reinforces the idea that cannabis is the answer. Many prefer cannabis as their medication for a variety of psychiatric conditions, despite evidence that it often only complicates treatment and worsens illness. It can be difficult to convince a patient that cannabis generally worsens depression, bipolar disorder, and psychotic spectrum disorders when its acute effects seem comforting and frankly enjoyable. It is also difficult to convince patients with anxiety and PTSD that, while cannabis has a salutary effect, continuous use often creates a rebound effect during withdrawal.

The protection of vulnerable populations requites government action, since there is no money to be made by the cannabis industry in preaching moderation. Government, as the communal responder to health problems, can regulate the cannabis industry to reduce rampant commercialization and marketing. Such regulations would not prevent the sale of cannabis products but would increase the safety of the products being sold. Government can also sponsor public education regarding the safe use of cannabis. All dispensaries should be required to post public health information guided by scientific evidence, including how to use cannabis safely, as well as specific warnings about the dangers of self-medication and mental health issues. This is not a restriction of free speech; rather, it is the exercise of free speech by officials elected by the people. Failure to improve regulations and education represents callous disregard for the damage cannabis can do to our most vulnerable citizens.

Meanwhile, multiple veterans groups are lobbying for greater access to cannabis through the VA and both houses of Congress have passed bills permitting VA doctors to write letters recommending medical cannabis in states where it is legal. (The VA, following federal law, cannot itself dispense or pay for cannabis.) Arguments regarding the civil right to access cannabis have trumped evidence-based public health concerns. Why? Because a combination of denial and ignorance about the science of cannabis prevents objective assessment of the risks for those who are most vulnerable.