Pot Could Affect Development of Teenage Brain
Using pot during a time when the brain is shaping itself in preparation for adult life could be detrimental, researchers say.
While advocates argue that marijuana is relatively harmless, studies show that smoking pot could have a detrimental effect on teenage brain development.
"[I]n childhood our brain is larger," said Krista Lisdahl, director of the brain imaging and neuropsychology lab at University of Wisconsin, Milwaukee. "Then during the teenage years our brain is getting rid of those connections that weren't really used, and it prunes back. It actually makes the brain faster and more efficient."
Using marijuana during this time is a very bad idea. "It's the absolute worst time," Lisdahl said, and further explained that our teenage years are the "last golden opportunity to make the brain as healthy and smart as possible."
Lisdahl cited a growing body of studies that suggests that regular pot use - just once a week or more - can affect the parts of the teenage brain that deal with problem solving and memory. One study showed that regular marijuana users have grades that, on average, are one point below their peers. Another study showed that marijuana users lost about eight IQ points between childhood and adulthood, while non-users did not lose any. And adults who use marijuana scored lower on memory tests than non-using adults.
But Dr. Gregory Tau said that these studies present a chicken-or-egg dilemma.
"It's very possible that there's something very different to begin with among teenagers who tend to get into trouble with marijuana or who become heavy users," Tau said, explaining why it could be these factors that drive people to marijuana use. "They could have subtle emotional differences, perhaps some cognitive functioning differences. It may be hard for them to 'fit in' with a peer group that's more achievement-oriented."
Though expressing doubts about the studies, Tau doesn't have any qualms with the idea that marijuana adversely affects the teenage brain. "It's not rocket science to think if you smoke weed when your brain is developing, that it can't be 'good' for you, just like any 'toxic' substance isn't good for you," he said.
Teenagers, however, don't seem to know about or care for such studies. In a recent federal survey, 60 percent of high school seniors believe marijuana is safe. Around 23 percent reporting using marijuana in the past month, more than alcohol and cigarettes. Six percent reported using pot every day, a number that has tripled over the past decade. Lisdahl said that more teenagers use pot in states where medical marijuana is legal and worries what will become of teenagers in states that legalize recreational pot.