The Future of Marijuana Research

In a previous study, not involving the van, she found that adults — including those over age 60 — who use cannabis exercise more often and enjoy it more. “The stereotype of the stoner snacking on the sofa may not be reality,” she says. “There's also some evidence cannabis users weigh less than nonusers. We want to learn more about that."

CannaVan study participants include pain patients, cancer patients, veterans, older adults and opiate users hoping to cut back. From start to finish, a study may take five years. “That's how long good research takes,” Bryan says. “But as the cannabis boom grows, I feel like we're the cart chasing the horse — and the horse is going faster and faster.”

Brain imaging

At Harvard University, Staci Gruber, an associate professor of psychiatry in the medical school, directs a program called MIND (Marijuana Investigations for Neuroscientific Discovery). Here, researchers use brain imaging and tests of thinking and memory to measure medical marijuana's effects on brain structure and function.

Participants must be fairly new to medical cannabis, use it at home and get checked at the lab about six times over two years.

The cannabis products participants use are analyzed by a private outside lab to give researchers clues to the marijuana forms and potencies associated with different effects over time.

"It's an observational study, not an intervention study,” Gruber says. “But it's important. Almost everything we know about marijuana comes from studies of recreational users who often started in their teens or early 20s, while their brain was still developing. They are different from today's medical marijuana users."

One surprise to emerge from MIND: In older adults, mental focus sharpened somewhat after three months of medical marijuana use; there was also more activation in their cingulate cortex, a brain area involved with paying attention, avoiding distractions and problem-solving. “We're seeing exciting changes in neuroimaging that may reflect normalization of brain function,” Gruber says. “Cognitive skills improve. It could be because people feel less pain, are sleeping better and are using fewer medications like opiates and benzodiazepines that can affect thinking and memory. Or it could be a direct effect of cannabis. We don't know yet.”

Gruber's lab is now developing a customized cannabis product for a future clinical trial, made from government weed. “It would be better if we could study the products people really use, but it's not like they have tinctures or capsules ready for us to play with,” she says. “So we're formulating a product from a muddy, tarry paste that's available from the government program. You have to think outside the box.”

It's worth the effort, she says. Right now, researchers are not only doing clever end runs around outmoded federal policies, they're also trying to answer questions raised by state-level medical marijuana policies that don't always have much evidence behind them (such as including glaucoma on a list of qualifying conditions, when marijuana has been shown to lack the consistent effect needed to treat the condition effectively). “Science helps set government policy. In the case of cannabis, [state] policy has outpaced science. Now we're trying to understand the good, the bad and the truth.”