7/7/2025
PITTSBURGH — Within months of Pennsylvania’s medical cannabis program adding anxiety as a qualifying condition, that diagnosis quickly rose to become the most common for cannabis certifications, according to a study by researchers at the University of Pittsburgh and Johns Hopkins University. The study was published today in Annals of Internal Medicine.
To date, 39 states have medical cannabis programs, with chronic pain and post-traumatic stress disorder (PTSD) historically being the most common and second-most common qualifying diagnoses, respectively, among participants. In recent years, several states, including Pennsylvania, have incorporated anxiety into their programs.
“We found that adding anxiety as a qualifying condition fundamentally changed the makeup of Pennsylvania’s medical cannabis program,” said corresponding author Coleman Drake, Ph.D., associate professor in the Department of Health Policy and Management at Pitt’s School of Public Health.
The researchers analyzed Pennsylvania Department of Health data on 1,730,600 medical cannabis certifications issued from November 2017, when anxiety disorders were added, to December 2023. These certifications require a physician visit and annual renewal.
The team found that the number of certifications issued each month nearly tripled during that time. Before the list of qualifying conditions was expanded, chronic pain comprised the lion’s share of diagnoses, at 67%, followed by 16% for PTSD. After anxiety was added, these numbers dropped to 41% and 11%, respectively, and anxiety quickly became the most common diagnosis, at 60%. Some certifications listed multiple conditions. The team was not able to determine how the overall size of the program was affected, nor how many participants had added or switched to anxiety from another diagnosis or were enrolling in the program for the first time.
Evidence supporting cannabis as an effective treatment for anxiety disorders is scant in comparison to other qualifying conditions, notably chronic pain, noted Drake.
“Adding anxiety to the program may inadvertently signal to patients that cannabis is effective for treating it, despite the lack of evidence, which is concerning,” he said. “At the same time, cannabis may improve some health outcomes, relative to alternative treatments, depending on the individual and their circumstances.” But, due to the red tape and funding scarcity that has historically restricted research on cannabis—as well as the lack of more granular data available from medical and adult-use cannabis programs—these unknowns persist, he said.
“The urgency in filling these knowledge gaps is pretty clear, given increases in cannabis use over the past decade, and the large changes in cannabis markets, like those we observed in this study,” said Drake.
Other authors on the study were Linh Tran and Matthew Eisenberg, Ph.D., of Johns Hopkins University Bloomberg School of Public Health.
Photos (Click image for high-resolution version)
Caption: Coleman Drake, Ph.D., associate professor, Department of Health Policy and Management, University of Pittsburgh School of Public Health
Credit: University of Pittsburgh
