Marijuana Not Benign: Warn Teens, Parents, AAP Says

Norra MacReady

February 27, 2017

As the legal status of marijuana evolves, pediatricians should counsel teenagers and their parents about its potential for harm, write the authors of a new clinical report from the American Academy of Pediatrics.

Despite the impression among many teenagers and their parents that marijuana is a fairly benign drug, it has some real risks that can have a longstanding effect on an individual's health and function, write Sheryl A. Ryan, MD, and Seth D. Ammerman, MD, and colleagues in the clinical report published online February 27 in Pediatrics.

A key area of concern is "the effect of its use on brain development," Dr Ammerman told Medscape Medical News.

There is also the concern that younger children may be exposed to marijuana in the form of edibles such as brownies that may be in the home, he noted. Already, there have been a few reports of children overdosing in this fashion in states where marijuana is legal.

As a result, "a lot of pediatricians now are being asked, 'is marijuana safe?' " he said.

The report arms clinicians with some information to answer that question. It addresses the effects of adolescent marijuana use and offers suggestions for conducting brief, office-based interventions aimed at identifying problem users and helping them stop.

It also provides a list of 10 talking points for pediatricians to remember when talking with parents and teenagers. The points stress the addictive nature of marijuana and its effect on the brain, the dangers of driving under the influence of marijuana, the toxicity of secondhand marijuana smoke, and the influence parents can exert as role models for their children.

Well-Documented Adverse Effects

The view of marijuana as a harmful substance has diminished among adolescents in recent years, the authors explain.

According to the National Survey on Drug Use and Health conducted by the US Department of Health and Human Services, only 41% of participants 12 to 17 years of age perceived "great risk" in smoking marijuana once or twice a week in 2015, down from 55% in 2007.

Yet many of its adverse effects are "well-documented," such as impaired short-term memory and concentration; alterations in judgment, coordination, and motor control; diminished lung function; and a heightened risk for mental health disorders such as depression and psychosis.

In addition, some studies have shown alterations in brain development in areas such as the amygdala, hippocampus, and prefrontal cortex, said Dr Ammerman, clinical professor, Division of Adolescent Medicine, Department of Pediatrics, Stanford University School of Medicine and Lucille Packard Children's Hospital, Stanford, California.

The clinical implications of these findings are unclear, he added, "but they're probably not good."

There is also clear evidence that marijuana is addictive, Dr Ryan, professor of pediatrics and associate clinical professor of nursing, Yale School of Medicine, New Haven, Connecticut, and colleagues write in the report. Overall, 9% of people who try marijuana become addicted, but that rises to 17% of people who try it during adolescence and anywhere from 25% to 50% of adolescents who smoke marijuana daily.

The risk is especially high among adolescents who are regular or heavy users of cannabis. Regular use is defined as 10 to 19 times per month, and heavy use is defined as 20 or more times per month.

Office Screening Suggested

The report urges pediatricians to screen adolescent patients for substance use, as recommended in the previously published Screening, Brief Intervention, and Referral for Treatment policy statement.

Screening should occur at all well-teen visits, or "whenever there is a concern that marijuana use might be an issue," Dr Ammerman said. He also suggested that even before they start screening, pediatricians should raise the issue with patients in an age-appropriate way.

Motivational interviewing techniques can be used either to support patients who have chosen to abstain or to discourage use among adolescents who do smoke marijuana. Some patients may require one or more follow-up visits or a referral to a mental health counselor, the authors write.

Clinicians can use the talking points to emphasize the drawbacks of marijuana: not only the adverse mental and physical effects, but also the fact that its use by people younger than 21 years is still illegal. Prosecution may result "in a permanent criminal record, affecting schooling, jobs, etc.," the authors state.

In addition, the talking points remind parents that they are role models for their children. "Actions speak louder than words," Dr Ammerman warned. "It's very clear that if parents use marijuana in front of their kids, those kids are more likely to use it themselves, regardless of what the parent says."

Adults who view marijuana as relatively harmless may be thinking of the product they used in the 1970s and 1980s, he added. Back then, the average dose of marijuana had about 4% tetrahydrocannabinol, or THC, the compound that gives marijuana its euphoric properties.

However, today's marijuana has 16% THC. "So the drug that we experienced is much less potent than what our children are using, and we know much more today about its potential problems."

On average, adolescents who become addicted to marijuana remain addicted for about 10 years, Dr Ammerman said. "So you've lost 10 years of your life, perhaps doing poorly in school or on the job, or in your relationships. We don't want anyone to throw their life away like that."

The authors have disclosed no relevant financial relationships.

Pediatrics. Published online February 27, 2017. Full text

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