Maryland now offers the country's first master's degree in the study of the science and therapeutics of cannabis. Pictured, an employee places a bud into a bottle for a customer at a weed dispensary in Denver, Colo. Bloomberg via Getty Images hide caption
Cannabidiol, or CBD, is a compound that can be extracted from marijuana or from hemp. It doesn't get people high because it doesn't contain THC, the psychoactive component of the cannabis plant. Getty Images hide caption
Evelyn Nussembaum and her son Sam Vogelstein pick up a six month supply of Epidiolex from the experimental pharmacy at UCSF. Lesley McClurg/KQED hide caption
A drug made from a derivative of marijuana has been approved for patients with certain forms of epilepsy. Blaine Harrington III/Getty Images hide caption
A sample of cannabidiol (CBD) oil is dropped into water. Supplements containing the marijuana extract are popular and widely sold as remedies for a variety of ailments and aches. But scientific evidence that they work hasn't yet caught up for most applications, researchers say. Stefan Wermuth/Bloomberg Creative Photos/Getty Images hide caption
The drug sold as K2, spike, spice or "synthetic marijuana" may look like dried marijuana leaves. But it's really any of a combination of chemicals created in a lab that are then sprayed on dried plant material. Spencer Platt/Getty Images hide caption
Cover art from Stoned. Current hide caption
Marijuana at a medical marijuana dispensary in Los Angeles. Twenty-three states and the District of Columbia have legalized medical marijuana. David McNew/Getty Images hide caption
