A lot of people are using the cannabis-extract CBD for anxiety relief, but scientists aren't sure if, let alone how, CBD allegedly reduces stress.

"CBD has gotten a lot of buzz," Richard Ferry - manager of Home Grown Apothecary in Portland, Oregon - told NPR recently. "My customers are buying CBD [for] stress relief...[But] there's a lot of confusion about how it [CBD] works and what it does exactly."

That's what researchers like Esther Blessing - a psychiatrist at New York University - are trying to figure out.

"I think there's good evidence to suggest that CBD could be an effective treatment of anxiety and addiction," she says. "But we need clinical trials to find out."

Her interest stems from a study in which CBD was used to help manage social anxiety. Study participants received either CBD or a placebo and the results were compared against each other.

"People who took CBD reported significantly less anxiety," Blessing says. "It's really interesting."

Blessing will soon begin a clinical trial to test CBD on people suffering with post-traumatic stress disorder and alcoholism. And since CBD doesn't contain THC - the psychoactive ingredient in marijuana - test subjects won't experience the mind-altering effects of smoking up. That means CBD could help patients can get through their lows without having to get high.