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A Perfect Storm

Marijuana use linked to loss of motivation, intellect, mental health and safety

The recent drug-related shooting death of 17-year-old Tyler Zanco in a Waltham, Mass., parking lot adds to the building storm clouds of illicit marijuana use by young people. According to police, Zanco, captain of his high school’s wrestling team, and two friends planned to rob a 21-year-old man they believe had cheated Zanco’s younger cousin of two ounces of marijuana in an earlier drug deal. After a fight ensued, a third man shot Zanco in the back as he tried to flee the scene.


Now we can add the blow back from a distinctly dark drug culture to the list of reasons it makes sense to keep kids away from weed—even the “fake” and potentially deadly kind highlighted on the April 21 cover of Time magazine.

The winding trail of prevention in recent times hails back to warnings that decriminalization and legalization of the drug would increase young people’s access to marijuana. Sadly, that prediction has come true. According to officials at the National Institute on Drug Abuse (NIDA), which in January released new Monitoring the Future data, there has been a precipitous rise in use of the drug among high school students.

Efforts by pro-marijuana groups to normalize perceptions of its use have worked. According to NIDA, 60 percent of 12th-graders do not view marijuana use as harmful. Perhaps that explains the significant increase in daily use of the drug by high school seniors from 2.4 percent in 1993 to 6.5 percent in 2013.

The two-decade trend does not only affect 17- and 18-year-olds. The same study, conducted by researchers at the University of Michigan, revealed that 4 percent of 10th-graders say they use marijuana daily, 18 percent report use in the past month, and almost 30 percent in the prior year.

A case in point: On March 29, the Boston Globe reported the arrest of three New Milford (Conn.) High School students, ages 14, 15 and 16, for selling marijuana-laced brownies at school.

But, wait. It gets worse. More than 12 percent of 8th-graders admitted to using marijuana in the last year.

And this is not their grandfather’s marijuana. According to NIDA Director Nora D. Volkow, the levels of THC—the main psychoactive ingredient in marijuana—have gone up from 3.75 percent in 1995 to an average of 15 percent in today’s typical dose. She goes on to point out, “We should be extremely concerned that 12 percent of 13-to-14-year-olds are using marijuana. The children whose experimentation leads to regular use are setting themselves up for declines in IQ and diminished ability for success in life.”

The smoking gun.

Similar themes can be found in an April 15 Boston Globe article that shares findings published in the Journal of Neuroscience: young adults who occasionally smoke marijuana show abnormalities in two key areas of their brain related to emotion, motivation, and decision making.

Some have stated that laws banning use of marijuana are ineffective. They are not.

Research from SADD (Students Against Destructive Decisions) preceding the loosening of drug laws, revealed that 65 percent of young people cited those very laws as the number-one reason they chose to not use drugs. That ground is now cracking under their feet.

Unfortunately, it’s also affecting their driving. New research from SADD and Liberty Mutual Insurance tells us that 13 percent of teen drivers say they drive under the influence of drugs, including marijuana. Of that cohort, 30 percent say it does not affect them negatively.

In truth, marijuana dampens alertness, inhibits concentration, distorts perceptions, and slows reaction times, none of which makes for safe driving. Even so, some kids actually believe that smoking marijuana makes them better drivers.

In a story in the New York Times, Marilyn H. Huestis, a senior investigator at NIDA, said, “It is clear that marijuana use causes deficits that affect driving ability,” citing a two-fold increase in the risk of a crash if there is any measurable amount of THC in the bloodstream.

Of course, there are also mental health issues related to the use of marijuana. The Harvard Medical School Family Health Guide points to motivation problems among chronic users and shares, “Research now indicates that marijuana use increases the risk of depression, as well as schizophrenia.” Notably, it states that depressed people do not use the drug more often than their non-depressed counterparts, seemingly solving the chicken-or-the egg conundrum.

Violence, intellectual declines, motivation and achievement shortfalls, crash deaths and depression. Sounds like a perfect storm … gathering too quickly among those too young.

Stephen Gray Wallace, an associate research professor and director of the Center for Adolescent Research and Education (CARE) at Susquehanna University, has broad experience as a school psychologist and adolescent/family counselor. He is also a senior advisor to SADD, director of counseling and counselor training at Cape Cod Sea Camps, and a parenting expert at For more information about Stephen’s work, please visit

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