BOSTON — Marijuana has become a booming business in Massachusetts since it was legalized in 2016. But there is growing evidence that some young people are becoming seriously ill, both mentally and physically, from using this drug.
That it is happening to youth cannabis users isn't a surprise to Dr. Staci Gruber, a leading expert on marijuana and its impact on the younger brain.
"Age matters," said Gruber. "We know that individuals who are using it at younger ages are more likely to have challenges or more pronounced changes."
Gruber, Director of Marijuana Investigations for Neuroscientific Discovery at McLean Hospital, said that's because the brain is still developing from adolescence well into adulthood.
"The young brain is vulnerable," she said. "It's vulnerable not just to things like cannabis, but to other substances, to alcohol, to illness, to injury, anything because it's under construction."
Her research compared the brains of people who use cannabis later in life to the brains of teenagers and young age who use the drug.
Gruber found one of the most striking impacts of cannabis on developing brains is what it does to white matter — a crucial network of nerve fibers that connects regions of the brain for fast and efficient communication. It's what she calls the "subway system" of the brain.
She can measure what's known as fiber tract integrity — essentially how well that "subway" is functioning — and her research revealed significant differences when it comes to cannabis' impact on younger br, developing brains.
"Earlier age of onset, lower white matter fiber tract integrity. Lower white matter fiber tract integrity, higher impulsivity," she explained. "It's like the perfect storm."
But the impact of cannabis use on younger brain can cause issues far beyond impulsivity, from cannabis-induced psychosis to more subtle changes.
"You may see all sorts of challenging behaviors from kids that is sort of an extreme version of what most people report they see in their teens," Gruber said. "Not necessarily always able to inhibit inappropriate responses."
Gruber acknowledged that teens using marijuana is nothing new. But she said the cannabis that's out there now is very different.
"The level of THC has gone up precipitously over the last several decades," she said. "These vape pens can have north of 90%."
That's 90% THC, the compound that produces the high when it comes to marijuana use. Just twenty years ago, that number was more like 10%.
"I'm pretty convinced that there may be a difference in the brain, especially if we're talking about people who are vulnerable and people who are just using concentrates," Gruber said.
She had this message for parents and kids:
"'Just say no' didn't work. So, we say 'Just not yet,'" Gruber said. "You're an adult for a very long time, and if you give your brain the opportunity to become fully developed, you'll probably have a better go of it.
