Researchers who study marijuana made a number of findings in 2015, from learning about the health effects of using the drug frequently and recreationally, to figuring out which diseases and conditions are most likely to benefit from the substance’s use.
The findings about marijuana that came out this year advanced the science, even if only incrementally, said Alan Budney, a professor of psychiatry at the Geisel School of Medicine at Dartmouth in Lebanon, New Hampshire, who studies behavioral treatments for reducing or quitting marijuana use. “It was perhaps more of a year of identifying important questions in need of answers,” he said.
A current major area of research investigates how the changing laws in some states governing marijuana use will affect rates of the drug’s use, including rates of problematic use, Budney said.
“A study this year published in the journal JAMA Psychiatry raised lots of eyebrows when it found a doubling of marijuana use among American adults and almost a doubling of problematic use between 2002 and 2013,” Budney told Live Science. Earlier studies of adult marijuana use had showed a much smaller increase.
Researchers are now wondering whether increased marijuana use will bring more problems, or if it will lead to fewer problems in other areas of addiction, such as alcohol, he said.
Another big concern in the field is the increase in sales of high-potency products, arriving with the advent of marijuana dispensaries in some states. “Little is known about the impact of these high-potency products compared with the lower-potency marijuana that people may have been using in the past 30 years,” Budney said. It’s too early, using the data that’s currently available, to know the effects, he said.
Researchers know that high-potency marijuana products are different than their low-potency counterparts. But what’s not known are what consequences may follow if more people have easier access to these stronger products, Budney said. The products may increase problems with toxicity, make users more prone to accidents and errors in judgment, and make more people vulnerable to addiction, he explained.
Some of the hottest areas of research are investigating marijuana’s short- and long-term effects on the brain, especially how use of the drug alters the course of brain development in teens, Budney said. Another hot topic is understanding the therapeutic benefits of compounds in marijuana used for medical reasons. [11 Odd Facts About Marijuana]
Although studies are beginning to show that some ingredients in marijuana are likely to be helpful for people with certain conditions, the findings have yet to nail down the specifics about the dose, the frequency, the best form to take (such as getting the active compounds from edible products or smoking it), the risks from frequent use, and whether marijuana works as well as or better than other available treatments, Budney said.