Marijuana is now more accessible — legally — than it has been since it was first banned in the “Reefer Madness” era of the 1930s, but that doesn’t mean researchers think we fully understand the plant or how its use affects people.
Far from it.
We know enough to say that marijuana has some legitimate medical uses and to say that in many ways, it’s less likely to harm users than substances like alcohol or opioids, but researchers still have a long list of questions.
Government regulations make the plant extremely difficult to study, which is one of the main reasons there are still so many things to learn about marijuana.
Business Insider recently spoke to several prominent researchers to see what they think the most important questions are — and what’s being done to answer them.
Here’s what they hope to find out.
How does marijuana affect casual users?
We know a fair amount how about how marijuana use affects chronic users, who sometimes see negative cognitive effects from that use — especially if they started when they were young. But researchers want to know more about how marijuana affects what’s probably the most common user — the “casual” user who doesn’t smoke every day or even every week, but just every so often.
This becomes more and more important as legalization makes marijuana more accessible.
How does marijuana affect kids when they first start using it?
Following kids over a long period of time is probably the best way to understand when and why they start using a substance, but researchers would never just give marijuana to kids and have them start using regularly, as that would be unethical. So for now, we don’t know how kids change after they first start using cannabis and other substances.
The ongoing ABCD study should help answer those questions. ABCD is a research effort that will follow 10,000 kids around the country — starting when they are 9 or 10 years old— for 10 years. It’s coordinated out of UCSD and there are 21 different sites around the country.
For this study, researchers will analyze the schools kids are enrolled in, examine at where they live, track images of their brains, see how much they exercise and sleep, and more. They’ll track everything from stress to puberty hormones to substance use. They’ll also see them before and after they begin experimenting with any substances, including marijuana, alcohol, nicotine, and other drugs.
When patients use medical marijuana regularly, how does it affect their life?
Even though we know marijuana can treat conditions like chronic pain, we don’t yet know how exactly that consumption will affect patients’ sleep, cognitive ability, brain activity, and general quality of life.
An ongoing study at the MIND program in Massachusetts should help answer those questions and more by following a group of medical marijuana users over time (longer than a year) to see how their health changes.
How does marijuana affect older adults?
We have lots of data on young users but little data on older users who might be starting to use for the first time or using again after not doing so for decades. This applies to new recreational users and to many potential medical users. Those older people are probably less susceptible to any of the potential negative brain changes that researchers fear very young users might experience if they start smoking regularly.
In fact, one of the first studies of older medical users from the MIND project had an encouraging finding. Their preliminary results showed that three months into their medical marijuana treatment, a group of patients (24 people, still relatively small) showed significant improvement in tests of cognitive function. Tests of heavy recreational smokers in the past have shown worse cognitive function. This was the opposite, though it can probably be explained by the fact that before treatment, pain could have impaired their cognitive abilities.