Cannabis Use & Brain Health: Are Young Marijuana Users At Risk Of Repeat Stroke?

The health benefits of marijuana are widely known as a solid treatment for multiple symptoms associated with chronic pain, anxiety,  multiple sclerosis, and cancer patients.

While the field continues to expand and evolve, the question arises: what are the downsides to cannabis use, if any?

A new American Heart Association's scientific statement published on Thursday in the Association's journal, Stroke, looks at some unanswered questions regarding the impact cannabis has on brain health, Medical Xpress writes.

"There's a lot of uncertainty in the medical community about the health effects of marijuana," said Fernando D. Testai, M.D., Ph.D., FAHA, writing group chair, professor of neurology and rehabilitation at the University of Illinois. "This scientific statement is intended to guide health care professionals in having a balanced and intentional discussion with patients about the potential known and unknown effects of marijuana on brain health."

The scientific statement, which follows a statement on marijuana and cardiovascular health, published in August 2020, will be presented and discussed during a symposium at the Association's International Stroke Conference in New Orleans.

Endocannabinoids, THC & Human Body

Humans naturally produces endocannabinoids, compounds similar to those in marijuana, which are involved in regulation of processes in the body, such as learning, memory, pain control and sleep.

Being essential to prenatal brain development as well as brain maturation during adolescence, the action of endocannabinoids is important.

With endocannabinoids as well as tetrahydrocannabinol (THC) - the main psychoactive compound in cannabis - being able to attach to neurons in the brain by using molecules called cannabinoid receptors, there's a possibility of disruption of the normal actions of endocannabinoids.

"These receptors are highly concentrated in brain areas related to cognition," said Testai.

The Statement

The statement stresses that previous animal studies in rodents suggest that prolonged exposure to THC can disrupt memory and learning and impact brain development and maturation if exposed to it at a certain age.

"Data obtained in these animal studies demonstrate that disruption of endocannabinoid pathways leads to behavioral and cognitive abnormalities, such as poorer memory and learning ability and a heightened sensitivity to stress," Testai explained. "Also, there may be vital life periods—gestation and adolescence—when the brain may be particularly vulnerable to the impact of THC."

However, the study on humans cannot replicate similar strict parameters due to marijuana exposure and social and environmental conditions being more easily observed in animal studies, which resulted in mixed results.

Nevertheless, similar concerns have arisen regarding the impact of marijuana exposure on brain health in humans.

The findings include:

• Worse scores on driving road tests when using THC-dominant marijuana instead of CBD-dominant marijuana or no marijuana.
• A decline in verbal memory in correlation to more years of self-reported exposure to marijuana.
• Children whose mothers had been using cannabis during pregnancy experienced more psychological problems and poorer cognitive function.
• Thinning in the prefrontal cortex of the brain in those who used marijuana during adolescence.
• Those using cannabis were found to have an increased risk of clot-caused stroke.

• Young Marijuana Users At Risk Of Repeat Stroke

In the meantime, a recent study led by researchers at Mercy Catholic Medical Center in Philadelphia, Pennsylvania revealed that young adults who already had a stroke, transient ischemic attack (TIA), or cannabis use disorder (CUD) are 50% more likely to experience a recurrent stroke in comparison with those not experiencing CUD, Medical News Today reported.

"Since marijuana use is more common among younger people and is now legal in various U.S. states, we felt it was crucial to study the risk of re-stroke […] especially with the established first-time stroke risk in cannabis users.," the lead author of the study Dr. Akhil Jain, told the news outlet. "We used recreational dependent or chronic/habitual cannabis use for our study, i.e., cannabis use disorder."

According to the Centers for Disease Control and Prevention data, more than 48.2 million people are using cannabis nationwide, with 3 in 10 cannabis users having cannabis use disorder (CUD).

Photo: Courtesy of Photo by Robina Weermeijer on Unsplash