How Much Do Researchers Really Know About Medical Marijuana You Ask?

As of last December, more than 30% of Americans live in states that have voted to legalize recreational marijuana use. A majority live in states that allow access to medical marijuana.

In many states, cannabis consumers can attend dinners, where multiple varieties of weed are paired with chef-prepared gourmet meals. In New York — a state with a relatively strict medical marijuana law — 98-year-olds like Ruth rely on cannabis oil to soothe the debilitating pains of neuropathy. Weed’s more legally accessible now than it has been since the Reefer as well as others. The varieties available now, created with the aid of modern botany and chemistry, are unparalleled in history.

With that in mind you might think that scientific researchers would have a pretty good handle on exactly how regular or casual marijuana use affects humans, how medical marijuana should be best used, and what potential risks there may be to cannabis use.

But if you thought that the recent warming towards marijuana is fully backed by scientific understanding, you might be surprised.

“There are so many basic questions that need to be addressed,” says Ryan, an associate professor of psychiatry who researches marijuana at Johns Hopkins Medicine. “The practical use and legalization of these things is happening faster than the science can keep up.”

A number of other experts say that even though we know far more about marijuana than we did just a few decades ago, there are important topics — ranging from questions about how marijuana affects the brains of different users to questions about how to make use of medical cannabis — where the legal policy has far outpaced the science. It’s not about being anti- or pro-marijuana industry, it’s simply that scientists want to know more — especially now, when it’s such an important topic because of the wave of legalization.

The Drug Enforcement Agency (DEA) considers marijuana a drug with no medical value, so it’s hard to get approval to research it and impossible to study the cannabis products most people use, since researchers can only give study participants cannabis grown at DEA-approved facilities. “It’s pretty amazing” that we have so many unanswered questions, says Staci, an associate professor of psychiatry at Medical School and director of the Marijuana Investigations for Neuroscientific Discovery program. “Its not new, it’s been around for thousands and thousands of years, it’s not like we just made this in a lab.” 

Many of the most common inquiries fit into three categories: questions about how recreational marijuana will affect users both young and old; questions about how medical marijuana affects patients; and questions about the marijuana plant itself.

And while marijuana is still distressingly hard to research, there are a number of ongoing studies that should help answer some of the most pressing questions.

Here’s what we’re learning from that research and what we still need to know.

The cannabis plant itself is a fascinating organism, one that humanity has used for thousands of years for reasons ranging from religious rituals to performance enhancement to just plain partying.

But within that plant there are somewhere around 400 chemical compounds, more than 60 of which are special compounds known as cannabinoids. These bond with a relatively recently discovered system in our brain that interacts with naturally-produced cannabinoids which is now being used by marijuana doctors in florida and other states around the country. In every animal, these natural (endogenous) cannabinoids play multiple roles, affecting mood, appetite, memory, consciousness, pain response, blood pressure, and more. The cannabinoids from marijuana tap into that same system, which is why the plant has such wide-ranging effects.

We’re pretty far from fully understanding how that system works and even further from understanding all the compounds in marijuana. The most famous cannabinoid, THC, is largely responsible for marijuana’s ability to get users high. Cannabidiol, CBD, is the next best known — it seems to be important for Florida marijuana doctors and many medical uses of marijuana. But those are still just two components of the plant. “We know a lot about THC and we’re starting to learn about CBD. “Out of about 400 compounds we know a decent amount about two.” That means there’s a lot to learn about which compounds might contribute to psychoactive effects and which might potentially have medical uses.

Further complicating this question is the fact that growers create numerous strains of cannabis with different characteristics. We see this most frequently now with high THC strains of marijuana. The data on this isn’t perfect, but it is true you can get stronger pot now than ever before, largely because of innovations in growing practices. About 20 years ago, a high THC concentration might have been 10 or 12%. In legal shops in Colorado and Washington now, it’s not hard to find concentrations of 18, 24, or even 30% THC.

Every tweak is going to change the health effects of the plant. High THC plants tend to have low CBD, for example, according to an associate professor of psychology and director of the Brain Imaging and Neuropsychology Lab. In general, THC potency keeps going up. Shesays this could be worrisome, since there is some research indicating that some of the brain changes seen in heavy marijuana smokers are not present in smokers who smoke higher CBD, lower THC strains. This could make the trend away from CBD a negative for some medical users.

Many wonder what will happen when THC concentration “goes up to 40,50, 60%.” People consume THC at those levels in some concentrated forms of cannabis, but we don’t know if that sort of consumption carries additional health risks or not. On the one hand, high potency stuff may be worse for cognition, but on the other, He says she’s had people tell her they smoke less when they use more concentrated products.

When it comes to marijuana, millions of people are using different types of cannabis products for supposedly therapeutic purposes. Different, strains, different concentrations, all consumed in different ways. He is studying the how different ways of consuming marijuana — orally, smoking, vaping — all affect the body. And while he says that not all of his work can be talked about yet, we do know that the mode of ingestion makes a big difference for how people feel the effects and how they manifest themselves.

Many substances might fall under the medical cannabis umbrella, but depending on their specific cannabinoid content and the means through which they are ingested, they’re going to have different effects. All those people using products for therapeutic purposes are “lacking information about which types of products to choose, what doses to use, and how cannabis compares to other medications,” according to Vandrey.

We do know that marijuana has legitimate medical uses — a recent report by the National Academies of Science, Engineering, and Medicine found a number of ways in which marijuana seems to be medically effective. But the report also noted that a lot more information about how marijuana and its various components affect users is needed.

At present, that’s hard to study. The marijuana that researchers can give people for experiments has to come from approved facilities and tends to be far weaker than what people actually use. A researcher in Colorado can walk into a store and buy marijuana but they can’t get approval to give that product to participants in a study.

Partially because of that, it’s even hard to measure what’s in these products. There’s no one approved system for testing cannabis products, so people running two different tests on marijuana samples might get different results. Those results might vary even more if they use a test meant for conventional marijuana (flower) on an edible. For those who really want to better understand the plant and to see how to use it most effectively to help people in a medical context, that’s a real problem.

Onething that’s absolutely critical is the development of standards around product manufacturing and labeling.

Some states have started to require that marijuana products be tested for potency and to make sure they are free of contaminants-Colorado, Nevada, Washington and Florida Medical Marijuana have rules that recreational and medical products be tested and Washington started to require testing after approving recreational marijuana, for example. However, it’s not clear that a fully accurate means of testing cannabis products exists yet.