A new federal report shows that the percentage of American high school students who smoke marijuana is slowly rising – while the use of alcohol and almost every other drug is falling.
The report raises concerns the relaxation of restrictions on marijuana, which can now be sold legally in 20 states and the District of Columbia, has been influencing use of the drug among teenagers. Health officials are concerned by the steady increase and point to what they say is a growing body of evidence that adolescent brains, which are still developing, are susceptible to subtle changes caused by marijuana.
“The acceptance of medical marijuana in multiple states leads to the sense that if it’s used for medicinal purposes, then it can’t be harmful,” said Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, which issued the report. “This survey has shown very consistently that the greater the number of kids that perceive marijuana as risky, the less that smoke it.”
Starting early next year, recreational marijuana use also will be legal in Colorado and Washington.
Experts debate the extent to which heavy marijuana use may cause lasting detriment to the brain. But, Volkow said one way marijuana might affect cognitive function in adolescents was by disrupting the normal development of white matter through which cells in the brain communicate.
According to the latest federal figures, which were part of an annual survey, Monitoring the Future, more than 12 percent of eighth-graders and 36 percent of seniors at public and private schools around the country said they had smoked marijuana in the past year. About 60 percent of high school seniors said they did not view regular marijuana use as harmful, up from about 55 percent last year.
The report also found, for example, drinking was steadily declining, with about 40 percent of high school seniors reporting having used alcohol in the past month, down from a peak of 53 percent in 1997. Cocaine and heroin use are at historic lows in almost every grade.
Cigarette smoking also has fallen precipitously in recent years. For the first time since the survey began, the percentage of students who smoked a cigarette in the past month dropped below 10 percent. About 8.5 percent of seniors smoke cigarettes daily, compared with 6.5 percent who smoke marijuana daily, a slight increase from 2010.
