Preliminary evidence from a new study led by Harvard Medical School affiliate McClean Hospital’s Staci Gruber, PHD, suggests that medical marijuana (MMJ) may not impair, and in some cases, may actually improve executive functioning in adults. A pilot study assessing the impact of medical Marijuana on executive function, assessed the impact of MMJ treatment on executive function and explored whether patients improved cognitive functioning. “After three months of medical marijuana treatments, patients actually performed better, in terms of their ability to perform certain cognitive tasks, specifically those mediated by the frontal cortex,” explained Gruber in a press statement.
Previous studies have shown that anxiety often interferes with both intention and executive function. So if MMJ products relieve anxiety, it is likely that a patient’s cognitive function may improve. Chronic pain also impairs cognitive performance, especially in tasks requiring executive functioning, so a reduction in pain will likely increase concentration and cognitive performance.
“Symptom improvement may therefore result in improved cognitive performance,” wrote the authors. “Interestingly, two previous studies have noted a positive association between the history of MJ use and improved cognitive performance on measures psychomotor speed, attention, working memory, executive functioning, and verbal learning in patients with bipolar disorder compared to patients without a history of marijuana use.”
The 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 completed several executive functioning tasks, such as the sharp Color Ward test, and the Trail Making Test, and the Wisconsin Card Sorting Test. After three months of MMJ treatment, participants completed tasks significantly faster, without making anymore errors,
The study also suggested that MMJ Products themselves may protect against the executive function deficits that effect most recreational marijuana users because of the inherent differences between MMJ and recreational MMJ products. MMJ products are often, but not always low in THC, the primary psychoactive constituent of the plant, and high in other cannabinoids, including CBD, which may also mitigate the negative effects of THC.