The first medical cannabis dispensaries in New York State opened in 2016, and by 2017, Julia Arnsten, MD, MPH, Chief of the Division of General Internal Medicine, was writing recommendations for patients at Montefiore’s Family Care Center (FCC). “We can certify people with certain severe, debilitating or life-threatening conditions such as degenerative joint disease, inflammatory arthritis, HIV, sickle cell anemia, fibromyalgia, and neuropathy,” said Dr. Arnsten, a registered practitioner with the New York State Medical Marijuana Program. “They also have to have an associated condition—for example cancer with pain, or multiple sclerosis with severe persistent muscle spasms.” (A complete list of conditions follows this article.)

Data from the first two years of the New York State program indicate that more than 70 percent of registered patients seek medical cannabis to treat chronic or severe pain. “It’s closer to 90 percent in my practice,” said Dr. Arnsten. Her patients range in age from 19 to 94. The 94-year-old is being treated for cancer-related pain. “The 19-year-old is a college student who had a terrible bone cancer,” said Dr. Arnsten. “He’s cured but still has pain and takes a high CBD form of cannabis during the day and a high THC form at night.” CBD (cannabidiol) is a cannabis ingredient effective against inflammation; THC (tetrahydrocannabinol) is active against neuropathic pain and is the compound that makes people high. Medical cannabis helps about half of people seeking pain relief, said Dr. Arnsten.

Dr. Arnsten has seen about 500 patients in her two-days-a-week practice at the FCC, which is “100 percent cannabis.” Other clinicians in her division are issuing recommendations at the Comprehensive Health Care (CHCC) and Comprehensive Family Care Centers and the Wakefield Campus, bringing the total of treated patients to about a thousand.

Many more patients may be self-treating, however, because “when they walk into the dispensary, the cannabis will cost them about twice as much as it would on the street,” said Dr. Arnsten. “The federal Drug Enforcement Administration classifies medical cannabis as a Schedule I substance, so insurance won’t cover it and registered dispensaries can accept only cash.” Some patients pay $200 or $300 a month out of pocket. Add to that the cost of getting to the dispensary. Licensed cannabis dispensaries are few and far between; there are currently four in Manhattan, two in Brooklyn, three in Queens, and only one in the Bronx, in Hunts Point. One of Dr. Arnsten’s older patients spent $200 in a month on carfare to a dispensary.

And so, instead, patients turn to local dealers. “I have no way to know what’s in the marijuana my patients bought, how they’re using it, or how it will affect their health,” said Dr. Arnsten. She prefers that her patients use the oil—“I’m not comfortable with smoking, whether it’s vape pen or combustible,” she said—but on the street, the smokable form is most common. Cannabis oil from a dispensary will have a label that gives the relative amounts of CBD and THC; on the street that is anyone’s guess, and there is always a chance of accidentally ingesting contaminants. Finally, buying on the street places patients at risk of arrest, “which is very detrimental to people’s health,” says Dr. Arnsten.

This health disparity cannot be a thing of the past until cannabis is legal everywhere in the United States. Lawmakers will need to overturn 1930s regulations that made marijuana illegal; society will need to demystify Nixon-era judgments about pot-smoking hippies and anti-war protesters. Dr. Arnsten belongs to Doctors for Cannabis Regulation, has testified on their behalf at state legislative hearings, and has joined letter-writing campaigns. She and colleagues Marcus Bachhuber, MD, formerly of Montefiore Einstein’s Division of General Medicine, and Gwen Wurm, MD, of the University of Miami Miller School of Medicine, recently published a paper in the Journal of Psychoactive Drugs surveying a thousand customers at an adult-use dispensary in Colorado, and “almost two thirds of them reported that the primary reason they use cannabis was to treat pain or insomnia,” said Dr. Arnsten. “The majority of those people said they’d been able to reduce their use of either over-the-counter or prescription pain or sleep medications.” A month after publication, the journal estimated that the article had reached 90 million people. And Montefiore Einstein investigators now have a five-year, $3.8 million NIH grant for the first long-term study of whether medical marijuana reduces opioid use among adults with chronic pain, including those with HIV. Lead investigator is Chinazo Cunningham, MD, Professor of Medicine and Associate Chief of the Division of General Medicine.

As of now, only 34 states have legalized medical cannabis, and 11 have legalized recreational or adult use, Dr. Arnsten said. But the outlook is positive: a Quinnipiac poll showed that a majority of Americans favor legalization, and medical practices can barely meet the growing demand for cannabis.