Impact of medical marijuana to be studied

As more states move toward legalizing the use of medical marijuana, the timing is right for researchers to start examining the impact of the substance on the brain.

Thanks to a $500,000 grant from best-selling author and mental health advocate Patricia Cornwell, researchers at McLean Hospital and Harvard Medical School are launching a study on the effects of medical marijuana on the mind.

“It’s a new thing to look at the impact of medical marijuana on cognition, brain structure and function,” says Staci Gruber, Ph.D., lead investigator, director of the Cognitive and Clinical Neuroimaging Core at McLean Hospital and associate professor of Psychiatry at Harvard Medical School.

No study has yet to assess the neuropsychological performance before, during and after treatment, according to a news release on the study. Other studies have looked at “potential therapeutic properties of cannabinoid chemicals delivered in standardized pharmaceuticals that have not yet reached the market.”

The District of Columbia and 23 states have legalized the use of medical marijuana, according to the release. The National Institute on Drug Abuse Web site says as of March 2014 at least 20 states had legalized the use of medical marijuana.

“At this point, policy has vastly outpaced science, with little empirical data available regarding the impact of medical marijuana on cognitive function, despite the legal status of the product in a growing number of states,” says Gruber. “Findings from this investigation will ultimately foster a greater understanding of the impact of medical marijuana on cognitive function and brain structure, and may in turn facilitate the examination of the efficacy of marijuana for the different disorders for which it is prescribed.”

The program, called the Marijuana Investigations for Neuroscientific Discovery (MIND) Program, will also gauge study participants’ perceptions of their own quality of life as it relates to medical marijuana treatment, according to the release.

“We are seeing the country’s view on marijuana shift dramatically and now is the time to allow science to inform our policies and our decisions,” says Cornwell in the release. She is a member of McLean Hospital’s National Council and was presented with the hospital’s highest honor in 2012 for her mental health advocacy. “The MIND Program has the potential to revolutionize what we know about medical marijuana and what we think we know.”

The grant creates the program, Gruber says.

Gruber says the first stage of the study is to assess individuals who are certified to use medical marijuana but who have not yet used the substance. Using neuroimaging, researchers will look at participants’ brains before the use of marijuana, then again after three months of use and again at six months and a year. She said the first stage will last about two years. Later stages include clinical trials.

“Given the considerable difficulty with cognitive function and disrupted mood experienced by patients with severe medical disorders, the addition of marijuana, which has shown promise in alleviating a range of symptoms, could potentially improve cognitive performance,” says Gruber in the release. “Equally critical, data showing a loss or impairment of cognitive function following the use of medical marijuana could inform alternative courses of treatment and prevent unjustified exposure to harm, especially in vulnerable populations.”