As the legality of cannabis drifts through a period of flux, the spotlight of scientific research is rarely far away. A new study, following heavy cannabis users, yields further insight into the drug's financial and social ramifications.

Both legal and public opinion of cannabis is changing in America.

Today, in Alaska, Colorado, Oregon and Washington, the possession and sale of cannabis for medicinal and non-medicinal purposes is legal.

Alongside these four states, another 15 are considering legalizing recreational cannabis use.

Washington, DC, legalized the personal use (but not commercial sale) of cannabis in 2015.

And a national survey conducted in 2013 found that 52% of Americans thought marijuana should be made legal.

The fate of legislation to legalize medical use of marijuana in Pennsylvania is in the hands of the state Senate - and lawmakers there have questions.

The legislation, Senate Bill 3, passed the House of Representatives March 16 on a 149-43 vote.

The Senate has two options – vote on the bill as it is and send it to the governor, or make additional amendments and send it back to the House for a second vote, said Fred Sembach, chief of staff for Sen. Mike Folmer (R-Lebanon).

Senators are questioning whether the bill can be implemented as passed by the House, Sembach said.

Former New Mexico Gov. and 2016 Libertarian White House hopeful Gary Johnson says he thinks President Obama is going to remove marijuana from the government’s “Schedule I” list of narcotics considered particularly harmful and addictive on his way out of office.

“It’s going to be just like alcohol,” Mr. Johnson told The Washington Times Tuesday. “I’m going to predict that Obama, when he leaves office, is going to deschedule marijuana as a Class I narcotic. I wish he would have done that to this point, but I think he’s going to do that going out the door. That’s a positive.”

The Oregon Health Authority says the production of cannabis extract is now a class B felony.

An Oregon Health Authority announcement that unlicensed production of marijuana concentrates will be considered a felony has effectively shut down Oregon's extraction industry for more than two weeks.

At a March 15 forum hosted by the Oregon Cannabis Association at Refuge PDX, marijuana business owners were surprised to learn that, under a law that went into effect March 3, unlicensed production of cannabis extracts—potent oils used to make concentrates and edibles— is considered a class B state felony.

A cannabis club in Colorado Springs is handing out free marijuana to military veterans, hoping to give them relief from issues like post-traumatic stress disorder and chronic pain they suffer from after returning home from deployment in war zones.

Over the weekend, the Veteran Farmers Alliance group handed out more than half a pound of pot and marijuana edibles – worth about $1,400 – to veterans in Colorado Springs. The group’s founder, Steve Defino, said other groups should also be doing the same thing and that marijuana was essential for him to deal with his PTSD, which he has fought for a decade.

The cannabis industry made $5.4 billion in 2015. Legally. That's $5.4 billion worth of businesses growing and cultivating plants, processing and shipping products, and selling marijuana, cannabis oil, and all manner of edibles at dispensaries. That figure is forecast to hit $22.8 billion by 2020 according to the latest State of Legal Marijuana Markets Report from ArcView Market Research and cannabis-focused data analysis firm, New Frontier.

Already a pioneer in high-tech and cutting-edge agriculture, Israel is starting to attract American companies looking to bring medical marijuana know-how to a booming market back home.

Since 2014, U.S. firms have invested about $50 million (34.9 million pounds) in licensing Israeli medical marijuana patents, cannabis agro-tech startups and firms developing delivery devices such as inhalers, said Saul Kaye, CEO of iCAN, a private cannabis research hub.

"I expect it to grow to $100 million in the coming year," Kaye said at iCAN's CannaTech conference in Tel Aviv this month, one of the largest gatherings of medical marijuana experts.

March 31 marks a new day in Detroit for medical marijuana. It's the last day for Medical Marijuana Caregiver Centers to apply for a license to operate in the city.

Before this, provisioning centers multiplied in a gray area of the law where they weren't exactly legal but were tolerated. That's an outgrowth of how Michigan's medical marijuana law played out when the courts ruled patients can have marijuana but didn't allow for venues to sell it. It's right in line with the weird machinations prohibitionists have always gone through to keep people away from the weed.

Ethan Nadelmann, executive director of the Drug Policy Alliance (DPA) and one of the most recognized speakers in drug-policy circles, doesn’t mince words when he gets up to talk at marijuana industry events. “Frankly,” he often says, “I am not interested in meeting most you.” The only people he wants to talk to, he tells his audiences, are those who are going to make a lot of money in the new marijuana industry in an ethical way and are interested in certain social issues that could make them ideal foot soldiers in the wider struggle against the global war on drugs.

What drug poses the biggest problem in your community? When Americans are asked, the biggest answer isn't cocaine, heroin, marijuana, or opioid painkillers. Instead, Americans point to a totally legal substance: alcohol.

Those findings come from a new survey by the Associated Press–NORC Center for Public Affairs Research, which asked more than 1,000 US adults to identify how big of a problem certain drugs are in their communities. The results point to alcohol as the biggest cause for concern: