Chronic pot use may have serious effects on the brain, experts say

As marijuana legalization builds momentum across the United States — with Michigan becoming the latest state to allow recreational use by adults — researchers are warning that more studies are needed on the long-term effects of chronic pot smoking on the human brain.

Marijuana is the most commonly used illicit drug in the United States, but little is known about its effect on health or how addictive it is.

According to a 2017 poll conducted by Marist College and Yahoo News, more than half of American adults have tried marijuana at least once in their lives, and nearly 55 million of them, or 22 percent, say they use it currently. Close to 35 million are what the survey calls “regular users,” people who say they use marijuana at least once or twice a month.

Full story at NBC News