Obtaining a medical marijuana card may pose a risk for people who use cannabis products to treat pain, anxiety or depression, according to a study conducted at the Massachusetts General Hospital in the United States, reports The Harvard Gazette.
In a significant minority of individuals, researchers found that people at greatest risk of developing the addictive symptoms of cannabis use disorder (CUD) were seeking relief from anxiety and depression.
This suggests the need for stronger safeguards over the dispensing, use and professional follow-up of people who legally obtain cannabis through medical marijuana cards, wrote Tracy Hampton of Massachusetts General Hospital (MGH) in a story published in The Harvard Gazette on 18 March 2022.
The study findings were published in JAMA Network Open.
“There have been many claims about the benefits of medical marijuana for treating pain, insomnia, anxiety and depression, without sound scientific evidence to support them,” says lead author Jodi Gilman of the Center for Addiction Medicine at MGH, and associate professor of psychiatry at Harvard Medical School.
“In this first study of patients randomised to obtain medical marijuana cards, we learned there can be negative consequences to using cannabis for medical purposes. People with pain, anxiety or depression symptoms failed to report any improvements, though those with insomnia experienced improved sleep.”
Particularly disturbing to Gilman was the fact individuals with symptoms of anxiety or depression – the most common conditions for which medical cannabis is sought – were most vulnerable to developing cannabis use disorder.
CUD symptoms include the need for more cannabis to overcome drug tolerance and continued use despite physical or psychological problems caused by the cannabis.
“Medical” cannabis has surged in popularity as 36 states and the District of Columbia in America have commercialised its use (as of December 2021) for myriad health conditions through medical marijuana cards.
These cards require written approval of a licensed physician who, under the current system, is typically not the patient’s primary care provider but a ‘cannabis doctor’ who may provide authorisation to patients with only a cursory examination, no recommendations for alternative treatments, and no follow-up. Indeed, the medical marijuana industry functions outside regulatory standards that apply to most fields of medicine.
MGH researchers began their trial in 2017 with 269 adults (average age of 37) from the Greater Boston area who were interested in obtaining a medical marijuana card.
One group was allowed to get the cards immediately, while the second group, designed to serve as a control, was asked to wait 12 weeks before obtaining a card. Both groups were tracked over 12 weeks.
The team found that the odds of developing CUD were nearly two times higher in the medical marijuana card cohort than in the wait list control group, and that by week 12, 10% of the medical marijuana card group had developed a CUD diagnosis, with the number rising to 20% in those seeking a card for anxiety or depression.
“Our study underscores the need for better decision-making about whether to begin to use cannabis for specific medical complaints, particularly mood and anxiety disorders, which are associated with an increased risk of cannabis use disorder,” says Gilman.
Regardless of the specific health condition for which cannabis is sought, Gilman believes that regulation and distribution of cannabis to people with medical marijuana cards must be greatly improved.
“There needs to be better guidance to patients around a system that currently allows them to choose their own products, decide their own dosing, and often receive no professional follow-up care.”
The study was funded by the National Institute on Drug Abuse.
Study details
Effect of Medical marijuana card Ownership on Pain, Insomnia, and Affective Disorder Symptoms in Adults – A Randomised Clinical Trial
Jodi M Gilman, Randi M Schuster, Kevin W Potter, William Schmitt, Grace Wheeler, Gladys N Pachas, Sarah Hickey, Megan E Cooke, Alyson Dechert, Rachel Plummer, Brenden Tervo-Clemmens, David A Schoenfeld and A Eden Evins.
Author Affiliations: Massachusetts General Hospital and Harvard Medical School.
Published online by JAMA Network Open on 18 March 2022.
Abstract
Despite the legalisation and widespread use of cannabis products for a variety of medical concerns in the US, there is not yet a strong clinical literature to support such use. The risks and benefits of obtaining a medical marijuana card for common clinical outcomes are largely unknown.
Objective
To evaluate the effect of obtaining a medical marijuana card on target clinical and cannabis use disorder (CUD) symptoms in adults with a chief concern of chronic pain, insomnia, or anxiety or depressive symptoms.
Design, setting and participants
This pragmatic, single-site, single-blind randomised clinical trial was conducted in the Greater Boston area from 1 July 2017 to 31 July 31 2020. Participants were adults aged 18 to 65 years with a chief concern of pain, insomnia, or anxiety or depressive symptoms.
Participants were randomised 2:1 to either the immediate card acquisition group (n = 105) or the delayed card acquisition group (n = 81). Randomisation was stratified by chief concern, age and sex. The statistical analysis followed an evaluable population approach.
Interventions
The immediate card acquisition group was allowed to obtain a medical marijuana card immediately after randomisation. The delayed card acquisition group was asked to wait 12 weeks before obtaining a medical marijuana card.
All participants could choose cannabis products from a dispensary, the dose, and the frequency of use. Participants could continue their usual medical or psychiatric care.
Main outcomes and measures
Primary outcomes were changes in CUD symptoms, anxiety and depressive symptoms, pain severity, and insomnia symptoms during the trial. A logistic regression model was used to estimate the odds ratio (OR) for CUD diagnosis, and linear models were used for continuous outcomes to estimate the mean difference (MD) in symptom scores.
Results
A total of 186 participants (mean [SD] age 37.2 [14.4] years; 122 women [65.6%]) were randomised and included in the analyses.
Compared with the delayed card acquisition group, the immediate card acquisition group had more CUD symptoms (MD, 0.28; 95% CI, 0.15-0.40; P < .001); fewer self-rated insomnia symptoms (MD, –2.90; 95% CI, –4.31 to –1.51; P < .001); and reported no significant changes in pain severity or anxiety or depressive symptoms.
Participants in the immediate card acquisition group also had a higher incidence of CUD during the intervention (17.1% [n = 18] in the immediate card acquisition group vs 8.6% [n = 7] in the delayed card acquisition group; adjusted odds ratio, 2.88; 95% CI, 1.17-7.07; P = .02), particularly those with a chief concern of anxiety or depressive symptoms.
Conclusions and relevance
This randomised clinical trial found that immediate acquisition of a medical marijuana card led to a higher incidence and severity of CUD; resulted in no significant improvement in pain, anxiety or depressive symptoms; and improved self-rating of insomnia symptoms.
Further investigation of the benefits of medical marijuana card ownership for insomnia and the risk of CUD are needed, particularly for individuals with anxiety or depressive symptoms.
Harvard Gazette story – Medical marijuana may trigger substance abuse (Open access)
See also from the MedicalBrief archives
Dosing, administering medical cannabis for chronic pain – Recommendations
Medical marijuana may bring relief to older people with chronic conditions
Patients hopeful for France's medical cannabis experiment
Teenage brains may be especially vulnerable to marijuana and other drugs