From vox.com

Marijuana has been with humans in some way or another for thousands of years. But after all this time, there is still a lot of public debate about what, exactly, pot’s risks and benefits are.

A recent review of the research from the National Academies of Sciences, Engineering, and Medicine attempts to fill the gap in our knowledge. By combing through more than 10,000 studies published since 1999, the review, conducted by more than a dozen experts, provides the clearest look at the scientific evidence on marijuana yet.

The research finds both some strong benefits and major downsides to cannabis. It seems to be promising for chronic pain, multiple sclerosis, and cancer patients. But it also seems to pose a significant risk for respiratory problems if smoked, schizophrenia and psychosis, car crashes, lagging social achievement in life, and perhaps pregnancy-related problems.

The findings aren’t just for marijuana; they’re for marijuana or cannabinoids, chemical compounds commonly found in pot. It’s possible that, down the line, some of the benefits in particular will be split from the marijuana leaf itself — although many drug experts believe that there’s an “entourage effect” with marijuana in which all of its cannabinoids and chemicals, which number in the hundreds, work together to make its effects as potent as possible.

One major caveat to this: The report is, by its own admission, only a best guess for a lot of its findings, because much of the research out there just isn’t very good. The report pins the lack of good research largely on government policies — particularly regulatory barriers linked to marijuana’s federal classification as a highly restricted Schedule 1 substance — that make it hard to conduct good studies on the drug. The National Academies ultimately calls for these barriers to be cut down and more research to be funded so we can get a better idea of what pot is capable of, especially as more states legalize it for both medical and recreational uses.

Still, the report is the best look at marijuana yet. It is nearly 400 pages; if you want a really deep dive into the benefits and harms of marijuana, you should read it in full. But here I’ve provided a summary of what the researchers found. 

Read more here