- As more and more teenagers use marijuana— a 2018 survey found 2.1 million middle and high school students have vaped the substance— research that looks into the health effects of cannabis is more important than ever.
- A new study in the Journal of Neuroscience found that after just one use of marijuana, the teenage brain can be altered.
- Researchers found that marijuana can increase the amount of gray matter in a teenager's brain, which affects adolescent development.
- Marijuana can also slow a person's reaction time, make their heart race, and affect short-term memory, INSIDER previously reported.
As more and more teenagers use marijuana — a 2018 survey found 2.1 million middle and high school students have vaped the substance— research that looks into the health effects of cannabis is more important than ever. And now, a study published on Monday in the Journal of Neuroscience demonstrates that marijuana can alter the teenage brain after just one use, NBC News reported.
To determine this, researchers scanned the brains of 46 14-year-olds from Ireland, England, France, and Germany. They found that those who used marijuana had higher brain volumes than those who didn't.
Specifically, the teens who used marijuana had more gray matter, a mass of cells that affect how humans mature over time, in their brains than those who did not use it.
"At the age at which we studied these kids (age 14), cortical regions are going through a process of thinning," Hugh Garavan, lead author of the study and a professor of psychiatry, told NBC News. When marijuana was introduced, however, the increased amount of gray matter "disrupted this pruning process" and therefore affected the normal maturation process, Garavan explained.
Marijuana can also slow a person's reaction time, make their heart race, and affect short-term memory
In addition to changing the teenage brain, marijuana also has other effects on the human body. When tetrahydrocannabinol, or THC, the main psychoactive component in marijuana, reacts with the body's cannabinoid receptors, a person may have slower reaction times than normal, INSIDER previously reported.
Additionally, marijuana can make a person's heart race temporarily. The National Institute on Drug Abuse said this feeling can last between 20 minutes and three hours and may cause a person's heart to increase up to 50 beats per minute.
A person who uses marijuana may also experience issues with their short-term memory since the substance affects how the brain processes information, according to a 2013 study.
Research has indeed shown that marijuana does affect the brain in long- and short-term ways, so people who use or are considering using the drug should consider the risks before proceeding.
Visit INSIDER's homepage for more.
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