Breaking with Tradition

What does legalizing medical cannabis mean for conventional pharmaceuticals?

Do people change their use of prescription medications when cannabis becomes a legal alternative? Father–daughter research team W. David Bradford and Ashley Bradford, from the University of Georgia, trawled through the data to uncover the truth, and their findings could play a part in the rescheduling of medical cannabis – as well as speaking volumes about public opinion.

The Bradfords analyzed data on prescription drug use in the US from 2010 to 2013, focusing specifically on patients covered by Medicare Part D, a federal government program that subsidizes prescription drugs for people over 65 – an age range thought to be most opposed to using cannabis. “It was a question of robustness,” says David Bradford, Adjunct Professor in the Department of Economics. “We had good data on Part D drug use, and believed that if we found an effect we could be confident that it was real. Ultimately, we were surprised at how statistically significant and robust the results were.”

The researchers estimated that implementing a medical marijuana law (MML) reduced Medicare Part D spending by about 0.5 percent in nine disease categories. Bradford breaks this down: “In 2013, that represents $165 million saved for the 17 states and the District of Columbia that had medical marijuana laws in effect. If all states had had a medical marijuana law in effect that year, Medicare Part D spending would have been about $470 million lower.”

The team has already examined the effect of MMLs on opiate-related deaths in the United States, and found that opiate deaths fell significantly when states implemented dispensary-based MMLs. They have also examined the impact of MMLs on Medicaid prescription drug use, and the findings were even more noteworthy: “The magnitudes in Medicaid were a good bit larger – 2 to 4 percent reductions in Medicaid spending when MMLs go into effect, compared with a one-half percent reduction for Medicare.”

The report certainly has garnered attention, both in scientific spheres and across the media, with references to the work made in at least one US Senate hearing. But the Bradfords were more interested in another implied aspect of the findings. “Patients and doctors together are treating medical marijuana as a real alternative to pharmaceutical medication,” says Bradford. This, if true, emphasizes the importance of further scientific research – with better health care the ultimate goal.


  1. AC Bradford, WD Bradford, “Medical marijuana laws reduce prescription medication use in medicare,” Health Aff, 35, 1230–1236 (2016).