Effects of Marijuana on Teens: How Marijuana Laws Change the Conversation

Thanks to the increasing trend toward legalizing marijuana, the conversation about the effects of marijuana on teens has gotten a lot more complicated. Prior to 2016, nearly half of the United States had legalized marijuana for medical use, and four states for recreational marijuana use by adults. With the November 2016 elections, however, seven new states have also legalized marijuana in some form. California, Maine, Massachusetts, and Nevada voters showed up to legalize recreational marijuana, while Arkansas, Florida, and North Dakota passed ballot initiatives legalizing medical marijuana. In total, marijuana is now legal for recreational use in seven states (AK, CA, CO, MA, NV, OR, WA) and the District of Columbia.

We asked experts how to talk to our teens about the effects of marijuana, in light of the changing map on marijuana laws and changing societal attitudes.

Ideas for How to Talk About the Effects of Marijuana

“It’s just pot.”
There’s a perception among teens—and some parents—that marijuana is harmless. “If smoking weed is legal, then I think some of my friends might not be so concerned with the cons,” says 18-year-old Olivia.

Indeed, in the most recent Monitoring the Future survey, which is funded by National Institute on Drug Abuse, the percentage of teens who said smoking pot was risky dropped below 40 percent. “The new laws in Colorado and Washington seem to say, ‘Pot is really no big deal, and this is exactly the wrong message for teens to hear,’” notes Stephen J. Pasierb, chief executive officer of The Partnership at drugfree.org. “The tween and teen years are the most critical from a developmental point of view to introduce a substance that interferes with brain functions.”

Brain science tells us that the human brain is not fully formed until about age 24. THC, the active ingredient in pot, can impact memory and learning. “This is not a legal or a moral issue— it’s about brain development. Ask your teen if they really want to play Russian roulette with their brain,” adds Pasierb. Dr. Ellen Rome, head of the Center for Adolescent Medicine, Cleveland Clinic Children’s Hospital, agrees that the effects of marijuana use on teens can have long-lasting negative impact on the structure and function of still developing brains: “Marijuana use affects the healthy formation of the prefrontal cortex and can interfere with the brain’s ability to transfer information from short term to long term memory.”

“Weed isn’t addictive.”
“Research supports the conclusion that marijuana is physically addictive,” explains Dr. Rome. In fact, statistics show that around 10 percent of adult users become dependent on marijuana. But because the symptoms can be mild—they include chronic lack of appetite—we may not notice when a teen is dealing with a marijuana addiction.

“People have a certain expectation of what addiction looks like, and with pot, the symptoms may not be as dramatic as they are for other drugs like heroin or methamphetamine,” notes Arthur Schut, President and CEO of Arapahoe House treatment facilities in Colorado. One thing is certain, however: marijuana dependence is “the primary reason for adolescent admissions to drug treatment,” says Schut. And marijuana dependence is now becoming an issue much earlier. Says Pasierb: “The average age of first drug use is in the early teen years.”

“But lots of adults smoke weed.”
“Parents must be clear with their teens that use of alcohol and other drugs, including weed, puts them at greater risk of harm—to themselves or others—and is not going to help them with school, sports or work,” says Sean Clarkin, executive vice president for Research and External Relations with Partnership for Drug-Free Kids. There’s a reason there are age restrictions on these substances, says Clarkin. “90% of addictions start in adolescence, when teen brains are still developing and learning coping strategies.” At the very least, Clarkin advises parents to their teen kids to “wait” until they’re in their twenties and can try weed at somewhat diminished risk. “When a teen has other risk factors—mental health disorders such as depression, anxiety or ADHD, or a family history of addiction, to name two examples—early use in adolescence is even more problematic,” Clarkin warns.

“It’s not even illegal anymore.”
Sure, adults over the age of 21 may now purchase marijuana for recreational use in 8 jurisdictions (AK, CA, CO, MA, NV, OR, WA, and District of Columbia). But possession of marijuana is still illegal and criminal under federal law—and possession by a minor remains illegal everywhere.

“Parents’ message on marijuana to their kids should essentially be the same regardless of legal status,” says Clarkin. “Marijuana is more dangerous for teens than for adults, not for legalistic reasons, but for science-based neurochemical reasons.”

“It’s safe—people use it as medicine.”
The American Medical Association considers marijuana to be a dangerous drug and a public health concern. Smoking pot “poses the same health risks of lung cancer and emphysema as smoking tobacco,” says Dr. Rome. Pasierb advises parents to tell their teens, “If you don’t have cancer or multiple sclerosis or glaucoma, then you don’t take medicine for diseases you don’t have.”

“Didn’t you smoke pot when you were young?”
Experts differ on whether parents should be honest about their own pot use, but whatever you decide, Pasierb cautions against moralistic or preachy arguments. “This message simply doesn’t resonate with teenagers,” he notes. Instead, redirect the conversation to ask your teen why he or she thinks marijuana is a good choice for them.

“You can’t stop me.”
What to do when a teen is adamant? At a minimum, urge the teen to wait until they’re in their mid-20s, when the brain is fully developed. That’s what Dr. Sanjay Gupta told his millions of viewers on CNN last summer, when he so publicly changed his mind on medical marijuana. Societal attitudes about marijuana are definitely changing, but that still doesn’t mean teenagers should be using it. The best prevention, say the experts, is to keep talking and listening regularly, being directly involved in your teen’s life, and making it clear that you do not want him or her using marijuana.


Jane Parent is senior editor of Your Teen. This article originally ran on Mar 21, 2014 and has been updated to reflect current laws.