It used to be all about the THC. In other words, cannabis' popularity has always been attributable to this psychoactive chemical, which gets people "high."

But marijuana's bad boy image has been getting a well-earned makeover in recent years, thanks in part to its surging popularity as a legitimate form of herbal medicine.

In fact, it's not cannabis' infamous THC content that's creating a real buzz these days. Instead, it's a lesser-known chemical called CBD that is attracting much of the attention. And it's all because CBD provides some of marijuana's most sought-after healing powers, according to medical studies.

Also known as cannabidiol, CBD is the second-most abundant cannabinoid in the marijuana plant. And here's what's really interesting: CBD does not induce the mentally intoxicating effects that have made cannabis so controversial. That's exclusively the role of THC.

This is great news for the majority of medical patients, who have little or no interest in feeling psychologically impaired, i.e. "stoned." All they want is a safe, addiction-free alternative to pharmaceutical drugs -- especially painkilling opioids.

All too often, opioids are over-prescribed by physicians. And they can quickly become very addictive.

They can induce all sorts of other nasty side effects, too. Worst of all, they have been blamed for many suicides.

Not surprisingly, a big part of medical marijuana's burgeoning appeal is that it doesn't come with the serious risks associated with opioids, and it's very rarely addictive.

Yet the full scope of its medicinal qualities is still not well understood, largely due to it being legally off-limits to most government-funded research facilities until recently. So the study of the 80 or so compounds that are found in the marijuana plant is still in its infancy.

This is why some government-endorsed growers of medical marijuana are hard at work developing strains of marijuana that are especially high in CBD but low in THC.

At the same time, the U.S. federal government is financing several dozen clinical trials into the efficacy of CBD as a treatment for a diversity of medical conditions. They include Parkinson's Disease, epilepsy, opiate addiction, Crohn's Disease, schizophrenia and cancer.

Now a Canadian licensed producer claims to have made a major breakthrough. Alberta-based Aurora Cannabis (CSE: ACB) just developed what is believed to be the most CBD-rich strain of medical marijuana in the world. And it's non-psychoactive.

This is according to Neil Belot, a company spokesperson. Until recently he served as the executive director of Canada's national trade association for licensed producers, known as the Canadian Medical Cannabis Industry Association.

"Independent lab tests during our qualification runs have confirmed this strain at nearly 26 per cent CBD and one per cent THC, which is a testament to our pioneering, science-driven plant cultivation technologies," Belot says.

"So we're confident that this will soon become Canada's most sought-after CBD-rich cannabis strain, and will be supported by physicians and patients alike," he adds.

Until last week, a strain developed in the U.S. called Charlotte's Web was considered to contain the highest percentage of CBD ever developed; it has 20 per cent CBD and less than 0.5 per cent THC.

The advent of non-psychoactive, CBD-rich/low-THC marijuana is a big step towards many peoples' acceptance of cannabis as a legitimate form of medicine. This is according to Dr. Jonathan Page, an adjunct professor of botany at the University of British Columbia in Vancouver.

A world-renowned expert on the chemistry of marijuana, he was the first scientist to sequence the cannabis genome. He now runs Vancouver-based Anandia Labs, a biotechnology start-up that's innovating new varieties of medical marijuana.

Page says CBD's anti-inflammatory properties may be particularly appealing to chronic pain sufferers who want to remain clear-headed while medicated. And CBD-rich oil is gaining greater acceptance among parents and doctors as an appropriate treatment for paediatric seizure disorders, including epilepsy, he adds.

Among its many other uses, CBD is considered therapeutic for treating depression, anxiety, insomnia and nausea.

Commenting on Aurora's unprecedented cultivation of the world's highest strain of non-psychoactive, CBD-rich cannabis, Page says, "This is a really remarkable achievement."

Follow HuffPost Canada Blogs on Facebook

MORE ON HUFFPOST: