Doctors across the country are seeing a growing number of people who are suffering from serious health consequences brought on by cannabis use, The New York Times reports.

Cannabis, legal in much of the U.S., is seen by many people as nonaddictive and safe. But psychiatrists are treating a growing number of people whose use of cannabis brings on psychosis symptoms including delusions and paranoia. Emergency departments across the country are treating patients with severe vomiting induced by cannabis, a once-rare potentially devastating condition that is now more common.

Gaps in state regulations, limited public health messaging and federal restraints on research have left many consumers, government officials and medical practitioners in the dark about serious health consequences of cannabis.

Many believe that people cannot become addicted to cannabis, but about 18 million people, nearly a third of adults who use cannabis, have reported symptoms of cannabis use disorder (CUD), and of those, about 3 million are considered to have addiction. More than 4.5 million young adults 18-25 use cannabis daily or near daily, and 81% of those individuals meet the criteria for CUD.