Does cannabis actually kill brain cells?

To put that longstanding head-scratcher to bed—or at least down for a long nap—The GrowthOp spoke with two medical doctors to better understand how cannabis affects the brain, and if the plant is actually killing brain cells when it's consumed.

Rumours swirling around the health effects of cannabis can get running far faster than the proverbial truth still focused on tying its shoes. However, the reality is that many claims often amount to unsubstantiated chatter at best.

Because there is still limited research on the long-term effects of cannabis use in humans, people interested in learning about everything from digestion to mood, brain function and pain management may feel as though they’re left to their own devices to come up with concrete answers. Consider, for example, the age-old question: Does marijuana actually kill brain cells?

To put that longstanding head-scratcher to bed—or at least down for a long nap—The GrowthOp spoke with two medical doctors to better understand how cannabis affects the brain, and if the plant is actually killing brain cells when it’s consumed.

Short-term consumption is the opposite of harmful

“In the short term, consumption of cannabis can actually have clear medical benefits in terms of depression, anxiety, pain, PTSD and nausea associated with chemotherapy,” says Dr. Ajeet Sodhi, a neurologist based in Thousand Oaks, Calif. “New studies are showing that the CBD compounds also have neuroprotective effects, and have been shown to be beneficial for several neurologic disorders such as epilepsy and multiple sclerosis,” Dr. Sodhi says.

While CBD is growing in popularity, it lacks sufficient long-term-use research, cautions Dr. Indra Cidambi, founder and medical director of the Center for Network Therapy (CNT), New Jersey’s first facility state-licensed to provide outpatient detox services for all substances of abuse.

“The medicinal properties of CBD appear promising, but they have not yet been proven,” Dr. Cidambi says. “There is no data that shows that CBD affects brain cells.”

Interestingly, cannabis in the elderly has been shown to improve cognitive health. Researchers at the University of Bonn in Germany discovered that small, daily doses of THC can reverse an aging brain and restore memory. The study was with mice, but it’s a start.

Long-term THC could affect users brains, depending on age

With regard to THC, it’s the long-term effects on the brain that raises red flags for Dr. Sodhi. “[Long-term cannabis use is] suspected to cause memory problems, lack of motivation, tolerance, contribute to worsen paranoia, and certain psych disorders such as schizophrenia,” he says. At this point in time, though, he says there simply aren’t enough studies that offer a definitive answer on whether or not long-term cannabis use affects the brain, and how.

Getting high does not equal killing brain cells

While frequent, heavy cannabis use can cause a dependency or even addiction in some people, as well as the possible aforementioned symptoms, there is some good news. Using marijuana, no matter the frequency, cannot actually “kill” brain cells in adult users, says Dr. Sodhi.

“Getting high is not synonymous with killing brain cells. The high is an altered state produced by the THC, a mild hallucinogen,” he explains. “Neither THC or cannabis ‘kills’ brain cells in the traditional sense, so there’s really no need to quantify damage to the brain.”

The higher the dose—for example, the more smoke a person inhales and holds in the lungs, or how many THC-laced cookies he or she swallows—will create a more intense high for sure, but as Dr. Sodhi points out, this does not cause increased neurotoxicity in the brain; it just makes a person more high.

For young people, however, marijuana and brain health is a different story. The spongy organs inside of children and teens have yet to fully develop.

One study found that those who heavily consumed cannabis as teenagers—and continued to consume into adulthood—lost an average of eight IQ points between the ages of 13 and 38. “More disturbing is the finding that these lost mental abilities did not return fully in those who quit marijuana use, even as adults,” says Dr. Cidambi. “Those who started using marijuana as adults, however, did not show notable IQ declines,” she notes.

“As a result of persistent drug use, the brain’s natural release of dopamine is suppressed and drugs stimulate the release of dopamine. That is how the brain is altered,” Dr. Cidambi explains. “It takes years for the brain to resume normal functioning.

In the interim, the individual addicted to marijuana, or any other drug, is prone to relapse as he or she does not feel normal without stimulated dopamine release from the brain,” she adds.

Remember: weed hasn’t made you stupider

If after blazing for years, decades even, you can’t remember where you left your keys or what you had for breakfast yesterday, it’s not dead brain cells from smoking weed that’s caused that forgetfulness.