Doctors report higher incidents of cannabis-related problems, such as confusion, anxiety, paranoia and hallucinations.
So far, 33 states have legalized medical marijuana and 11 have approved adult recreational use. Here's a look at which states could be next.
The recreational cannabis industry, which is fully legal in 11 states, will continue to face onerous levels of red tape and uncertainty well into 2020.
Rep. Pramila Jayapal criticized former Vice President Joe Biden's weekend statements on marijuana, saying "Prohibition is a gateway to racist policing practices and mass incarceration, though."
In the 11 months since recreational use became legal in the state, police have had to change the way they dealt with situations where marijuana smells are present.
Two Pennsylvania state senators introduced Senate Bill 350 on Tuesday which would allow adults 21 and older to possess, cultivate and purchase cannabis from licensed retailers.
U.S. Surgeon General Jerome Adams and HHS Secretary Alex Azar, both Trump-appointed officials with drug company ties, issued a national warning Thursday about marijuana legalization and increasing potency.
Democratic presidential candidate Andrew Yang pointed to legalized pot as a potential factor behind a Colorado poll released Tuesday showing him far higher than in other primary states.
Omar noted that Americans are still being jailed under harsh anti-drug laws, even though several states have already legalised recreational marijuana use.
"Personally, I would still favor one uniform federal rule against marijuana," Barr said. "But if there is not sufficient consensus to obtain that then I think the way to go is to permit a more federal approach so states can, you know, make their own decisions within the framework of the federal law."
Licensed farms can harvest 9 million pounds of cannabis, but the demand is only 1.8 to 2.2 million, the report said.
Representative Earl Blumenauer of Oregon introduced a bill to regulate marijuana the same way the government currently regulates alcohol products.
Deputy Prime Minister and Justice Minister Prajin Juntong explained that legalization would be carried out and managed under direct government control to ensure that "all benefits will go to the Thai people and the country."
Michigan still needs to figure out licensing and other regulations.
While many Canadians may be driving stoned, police across the country have not noticed an uptick in pot-impaired drivers in the past month.
Officers did, however, raise concerns that more awareness is necessary around laws about properly storing cannabis in vehicles.
Marijuana industry businesses blame stringent regulations as one of the driving factors behind a lack of supply.
"Legalization is happening at a much more rapid pace than expected, even compared to, say, 12 months ago," C21 CEO Robert Cheney said.
"Seeing our neighbors making progress should put much more pressure on us to get it right and ditch our outdated federal marijuana policy," Democrat Congressman Earl Blumenauer from Oregon told Newsweek.
"The effects caused by marijuana do not justify an absolute prohibition on its consumption," the court ruled.
South Korean citizens are subject to the country's strict drug laws even when abroad.
"It's a nice feeling to no longer be looked at as a criminal," said Ian Power, who has been using cannabis since he was a teen to manage pain.
Despite the federal prohibition on cannabis, the majority of Americans—both Democrats and Republicans—support recreational legalization.