The study, “Splendor in the Grass? A Pilot Study Assessing the Impact of Medical Marijuana on Executive Function,” led by Staci Gruber, PhD, also explored whether patients experienced improved cognitive functioning, reports Cynthia Than at Inc.
“After three months of medical marijuana treatment, patients actually performed better, in terms of their ability to perform certain cognitive tasks, specifically those mediated by the frontal cortex,” Dr. Gruber explained.
Anxiety Relief Equals Improved Cognition
Previous studies have already shown that anxiety often lessens both attention and executive function, so if cannabis products relieve anxiety, it makes sense that a patient’s cognitive function improves. Chronic pain also impairs cognitive performance, especially in tasks requiring executive function, so a reduction in pain level likely increases concentration and cognitive performance.
“Symptom improvement may therefore result in improved cognitive performance,” the authors wrote. “Interestingly, two previous studies have noted a positive association between a history of MJ use and improved cognitive performance on measures of psychomotor speed, working memory, executive functioning, and verbal learning in patients with bipolar disorder compared to patients without a history of marijuana use.”
Subjects in the study completed the Wechsler Abbreviated Scale of Intelligence, “which provides an estimate of overall cognitive functioning, to ensure an estimated IQ of 75 or higher,” according to the study. Each participant also completed several executive functioning tasks. These included the Stroop Word Color Test, the Trail Making Test, and the Wisconsin Card Sorting Test.
Performance Significantly Improves After 3 Months
After three months of medicinal cannabis treatment, participants completed tasks significantly faster, without making any more errors.
“Further, patients reported some improvements on measures of clinical state and general health as well as a decrease in conventional pharmaceuticals, notably opiate use, which was reduced by 42% between the baseline and Visit 2 assessment,” the study’s authors noted.
More than 22 million Americans report current use of recreational marijuana, and more than 1 million are certified for medical cannabis use, according to the Center for Behavioral Health Statistics and Quality.
CBD A Factor?
The authors speculate that the greater presence of CBD (cannabidiol) in medical marijuana products may be part of the answer as to why medicinal cannabis users don’t experience the cognitive deficits seen in some recreational marijuana users.
Gap Between Science and Policy
Since medical cannabis users in the study didn’t experience the cognitive deficits commonly observed in recreational users, the authors believe that “it is in the public’s best interests to develop a robust, evidence-based understanding of both the positive and negative effects of MMJ use on various aspects of functioning: cognition, quality of life, physical and emotional health.”
“Given its Schedule I classification, research studies exploring both potential risks and benefits of MMJ have faced numerous obstacles, forcing policy to outpace science in recent years,” the authors write. “As the national climate warms toward MJ, research is slowly pushing forward. However, much is left to be explored before the gap between science and policy can begin to close.”