top of page
  • Writer's pictureAshley Slimak

Cannabis Myths Series: Does Cannabis Kill Brain Cells?

Arkansas Marijuana Card Myths About Cannabis
Arkansas Marijuana Card's 'Myths About Cannabis' Series

In our new series, "Myths About Cannabis," we will be focusing on the misconceptions that are often associated with marijuana while providing insight and context to debunk each myth.

The first topic in this series that will be addressed is one of the most proven myths surrounding marijuana use: marijuana kills brain cells.

This popular myth has continued to be one of the most damaging to the reputation of cannabis. During the Reagan administration, anti-drug campaigns began to take off. It was in 1987 that one of the most notorious public service announcements was published, “this is your brain on drugs,” which showed an egg being fried in a pan.

The myth of cannabis killing brain cells originated from American psychiatrist, Dr. Robert Heath who conducted a study on monkeys. Dr. Heath found in his study that changes in the brain cells of the monkeys were taking place due to their exposure to high doses of cannabis. More importantly, his research supposedly did not report any brain cell death, although it was alleged.

However, Dr. Heath's research allegedly found that there had been brain damage in three of the monkeys tested that had been “exposed to heavy doses of cannabis.” Although this may raise some concern, the results of the study have fortunately never been successfully duplicated. In fact, his study has since been discredited by larger studies. Two of these include Dr. William Slikker of the National Center of Toxicological Research along with Charles Rebert and Godron Pryor of SRI International. Neither of these two studies found any evidence supporting "any evidence of physical alteration in the brains of monkeys exposed to daily doses of pot for up to a year."

The theory behind Dr. Heath's study was that the examined brain alterations were a result of oxygen deprivation and brain suffocation, not cannabis. There are a number of experts who believed Heath’s original study made the monkeys wear gas masks that were consistently being filled with cannabis smoke, which did not allow the monkeys to have an opportunity to get fresh air. Due to the conditions, the monkeys began to experience suffocation which then lead to the observation of dead brain cells. Brain cells become very sensitive when there is a lack of oxygen, and some cells can begin dying in less than 5 minutes after oxygen deprivation.

Does Marijuana Kill Brain Cells Dr Heath study
An illustration depicting Dr. Heath's study showing the monkey being exposed to cannabis.

Dr. Perry Solomon, chief officer at, and a retired anesthesiologist stated that “Every study shows that it just doesn’t kill brain cells. But, while studies have shown that cannabis use doesn’t lead to permanent brain damage, there is the possibility of temporary negative effects for those who use the substance.”

The negative effects associated with cannabis use have been shown to occur mostly on a short-term basis. In 2001, A Harvard University study found that heavy cannabis-users had normal memory test scores within a month of testing, and found that cannabis does not cause irreversible mental defects.

Experts say the brain is not fully developed until the age of 25. Excessive cannabis use during the developing stages could still run some risk of negative mental health effects. However, further research is necessary to study other factors and circumstances that may cause these negative effects.


Arkansas Marijuana Card Logo
Arkansas Marijuana Card Doctors

If you are an Arkansan suffering from one of these 18 medical conditions you may be eligible to treat your ailment with medical marijuana, which includes both THC and CBD products.

Click here to learn more about what Arkansas Marijuana Card's state-certified medical marijuana doctors can do for you, or give us a call at (844-249-8714) and our friendly support team can walk you through the entire process, and set you up with an appointment.

337 views0 comments


bottom of page