As new research shows the susceptibility of the adolescent brain to marijuana use, new laws - such as those in the District of Columbia and Maryland - may be sending conflicting signals to teens and parents about the effects pot has on learning, memory, impulse control and emotional regulation. "So many kids say marijuana is not nearly as bad as alcohol. As therapists, it's tough to dissuade them. One of the discussions we used to have is that marijuana is illegal, but that's not the case everywhere anymore," says Robyn E. Brickel, a psychotherapist and the director of Brickel and Associates, LLC in Alexandria, VA.

"With all the hype surrounding legalization and decriminalization, young people are taking that to mean it's not dangerous," says Beth Kane Davidson, Director of Suburban Hospital's Addiction Treatment Center in Rockville, MD. "We're seeing marijuana use start at earlier ages because of that perception."

This is a concern to mental health and addiction specialists. "The average age of onset for kids who become addicted to marijuana is 12," says Brickel. Roughly one in six people who start using as a teen and as many as 50 percent of those who use it every day become addicted to pot, according to the National Institute on Drug Abuse (NIDA).


Adolescence is a time of major brain development - development that does not conclude until a person's mid-20s. While marijuana's short-term effects, such as mood changes and munchies, are well known, its long-term effects on the brain are only beginning to be understood.

"Marijuana use actually does reduce cognitive capacity. It does so constantly and not just while a kid is high," says Robert Roth, Coordinator of Adolescent Services at MedStar Montgomery Medical Center in Olney, MD. "Research shows that they are losing up to eight IQ points." There is, he adds, no consensus as to how long the ill effects last. "Stanford did a study showing that after 12 to 16 months with no marijuana use the brain returns to where it was. But there are other studies that conflict with that." From his own experience, Roth says that those who "start using in middle school, even if they stop before college, find it harder to learn new things and remember things. They have more difficulty handling a complex task."

"So, what is the risk worth to you?" That's the question Davidson poses to the teens with whom she works. "When they tell me they want to go to college, I ask, 'Why are you playing Russian roulette with your brain?' I urge them to give it more time. Maybe when they are 25 or 30, and their brains are fully developed, we'll have research that will help them make an informed decision about what they are doing to their brains."

Chemical Composition

Delta-9-tetrachydrocannabinol, also known as THC, is the active ingredient in marijuana. "It's what causes the distortion, the mind-altering effect," says Davidson. And those effects are more significant than what they were decades ago.

"This is not the marijuana their mothers or grandmothers smoked," says Roth, noting that the THC content in the pot today's teens are smoking has increased. Many parents, especially if they used marijuana as teenagers, are thinking of a substance that is not nearly as potent as what currently is available.

"The concentration of THC is significantly greater today," says Brickel. "In 1976, marijuana had about 2 percent THC; by 2005 it was 5.2 percent; and in 2013 it was 15 percent … What [kids] are experimenting with today is something so much more addictive."

And that's just the potency of leaf marijuana. Marijuana wax - a product that, while smoked, has the consistency of lip balm - can contain as much as 90 percent THC, according to Roth. "When we do a drug test … showing the amount of THC in the system, something in the 200-300 range would have us concerned. Kids using wax can come in at over 1,000," he says.

Edibles are also a concern. While the buzz from eating marijuana takes longer to kick in, the high often lasts longer, due to the concentration of THC. That, along with the ways in which the edibles are being marketed, has Davidson concerned. "Product design includes gummi bears and THC lollipops," she says. "The whole marijuana culture is exploding into products that, in my view, are very attractive to young people."


When someone uses marijuana, activity in a part of the brain known as the hippocampus is reduced. Such a disruption can cause problems with short-term memory, making it more difficult to learn new things and recall recent events, according to NIDA. THC also affects the parts of the brain that control balance, coordination and movement.

Judgment is impaired by the presence of THC. Teens, due to the fact that their brains - specifically the prefrontal cortex - are still works in progress, are prone to risky behaviors that provide instant gratification. Take that predisposition and combine it with the effects of THC and the potential for impulsive actions is even greater, notes the NIDA website.

Pot also affects the neurotransmitter dopamine, which is responsible for feelings of pleasure and euphoria. Long-term use of marijuana can change the balance of these neurotransmitters. As a result, kids no longer experience the effect of dopamine in a natural way and may smoke marijuana again and again to feel high, explains Brickel.


Roughly 15 percent of eighth-graders report having tried marijuana, according to a 2014 NIDA survey. That number increases to just over 44 percent among high-school seniors - with 35 percent having used pot in the past year, 21 percent in the past month and nearly 6 percent on a daily basis.

So, why do kids use marijuana? "The number one response is boredom. The real reason is peers, followed by anxiety and depression," says Roth.

Davidson concurs and adds another reason why teens try pot - curiosity. "We want kids to be curious. The world is full of things to explore - but drugs shouldn't be one of them. We need to educate them as to what drugs will do and provide them with guard rails," she says.

"Teens also turn to marijuana as a form of self-medication," says Brickel. "They smoke pot to escape the stress in their lives, calm down or feel less anxious. But, often, they end up feeling even more anxious," she says. This is particularly true with teens that have mental health issues. "They are more susceptible when someone says, 'This will make you feel better.'"

Teens that may be genetically predisposed to mental health problems could find that marijuana use "pushes them over the edge," says Roth. "Recent research shows that marijuana poses a risk to these kids because it acts in the same way as certain hallucinogens."

Given society's increasing acceptance of recreational use of marijuana among adults, mental health professionals see a need to educate kids about the short- and long-term effects of pot. Davidson frames it as brain protection. "We've become such advocates of helmets - ensuring our kids put them on to avoid a concussion. But, when you think about it, marijuana is jostling the brain just as much - just in a different way," she says. "We owe it our kids to protect their brains in every way possible."

Karen Finucan Clarkson is a Bethesda-based freelance writer and mother of three sons - a recent college grad, a college junior and a high school freshman.