There is no prescription for concussions; the standard treatment is simply to rest until the symptoms fade. But the unseen damage from repeated concussions doesn’t really fade—and it can change the brain in ways that may take years to surface. For those unlucky enough to develop CTE, the brain gradually descends into a state of progressive degeneration associated with memory loss, impaired judgment, loss of impulse control, aggression, depression, suicidal thoughts, and—ultimately—dementia.

Despite the apparent need for research like theirs, the Miami research team has a challenging road ahead—starting with the legal hoops they must jump through to get the compounds they need. Marijuana, a schedule 1 drug, is notoriously difficult for researchers to obtain, and CBD is no easier. “As far as the DEA is concerned, they’re the same,” says Hoffer. “While almost all doctors have class 2 through 5 licenses, getting a class 1 addition to your license requires a lot of paperwork.”

When they begin clinical trials in about a year, the team will be stepping into relatively uncharted territory. Not only will this be the first large-scale study in the U.S. to look at cannabinoids as a treatment for concussions, it will be one of just a handful of concussion treatment studies currently underway.

“Designing treatments has not really taken off because, despite the fact that millions and millions of people are having concussions every year, we’ve just been behind the game,” says David Wright, a neurologist at the Emory University School of Medicine. Wright also studies traumatic brain injuries, although his work focuses on moderate to severe head trauma rather than concussions. In 2014, he led a study investigating the hormone progesterone’s effect on traumatic brain injuries. It proved unsuccessful despite promising preclinical trials.

“Right now, we’re all trying to better define the disease and figure out what in the world is going on,” he says.

One reason concussions are tricky to study is that they are difficult to define. There is no one characteristic doctors can use to diagnose a concussion beyond doubt. “It’s a clinical system, almost like a psychiatric disorder,” says Wright. “So there’s not currently a good marker.”

To deal with this, the Hoffer and his colleagues at the University of Miami will use I-Portal goggles, a device that measures eye movements to diagnose concussions with 95 percent specificity. The team tested the device with a 2014 grant from the NFL. Hoffer also says that each individual patient’s criteria will be clearly recorded, so that later on the researchers can see if all the patients with headaches, for example, respond differently from those with dizziness.

Another challenge will be figuring out how to measure whether patients’ brains are truly healing. “We don’t know what’s going on microscopically within their brain, but at least functionally their memory and things like that return back to normal [without treatment],” says Wright. The team plans to draw from peer-reviewed research to find measures that have proven successful in other studies.