Cigarettes, alcohol and prescription painkiller abuse among teens has declined since 2013. However, electronic cigarettes have surpassed traditional smoking in popularity among teens, according to an annual report released Tuesday from the U.S. Centers for Disease Control and Prevention. It's the first time e-cigarettes have been included in the survey.
The report found that marijuana use appeared to level off after recent increases, with 6.5 percent of eighth-graders reporting they'd smoked pot in the past month, along with 17 percent of 10th-graders and 21 percent of 12th-graders. Nearly 6 percent of high school seniors reported daily marijuana use.
Fewer teens are trying synthetic marijuana, dangerous drugs known by such names as K2 and Spice. About 6 percent of seniors said they had used synthetic pot this year, down from 8 percent last year and 11 percent in 2012.
Abuse of prescription painkillers is also dropping among teens. Six percent of high school seniors reported using the narcotics without medical supervision in the past year, down from 9.5 percent a decade ago. This may be especially surprising since health officials have sounded the alarm on increasing rates of opioid overdoses.
Even binge drinking has declined, although alcohol remains the most widely abused substance. Approximately 1 in 5 high school seniors reported binge drinking, defined as five or more drinks in a row, in the previous two weeks. The 2009 edition of the report put the number at 1 in 4.
But the use of e-cigarettes reached levels that surprised researchers. This year's report, which was funded by the NIH's National Institute on Drug Abuse, marked the survey's first attempt to measure the use of e-cigarettes by people in that age group.
Nearly 9 percent of eighth-graders said they'd used an e-cigarette, in the previous month, while just 4 percent reported smoking a traditional cigarette.
E-cigarette use increased with age. Some 16 percent of 10th-graders reported "vaping," or using an e-cigarette, in the past month, along with 17 percent of high school seniors. Regular cigarette smoking continued inching down, to 7 percent of 10th-graders and 14 percent of 12th-graders.
Young people may mistakenly believe they carry no health risks. "The perception is that they're safe," said CBS News chief medical correspondent Dr. Jon LaPook. "After all, there's no tar in them; tar is the substance in traditional cigarettes that's been linked to cancer. But we don't really know what the risks are of this vaporized substance."
He noted one study from the FDA that found a number of hazardous chemicals, "even potentially some cancer-causing chemicals," in e-cigarette vapors. "The FDA is very concerned not only about what's in these e-cigarettes but also the fact that they have nicotine and nicotine is highly addictive. And it can have effects on the developing brain, which is the age group it's being marketed to," he said.
"I worry that the tremendous progress that we've made over the last almost two decades in smoking could be reversed on us by the introduction of e-cigarettes," said University of Michigan professor Lloyd Johnston, who leads the annual Monitoring the Future survey of more than 41,000 students.
E-cigarettes often are described as a less dangerous alternative for regular smokers who can't or don't want to kick the habit. The battery-powered devices produce vapor infused with potentially addictive nicotine but without the same chemicals and tar as tobacco cigarettes.
The survey didn't ask about repeat use, or whether teens were just experimenting with something new. But between 4 percent and 7 percent of students who tried e-cigarettes said they'd never smoked a tobacco cigarette, noted University of Michigan professor Richard Miech, a study senior investigator.
"They must think that e-cigarettes are fundamentally different," he said.
E-cigarettes began to appear in the U.S. in 2006 but this was the first year that the Monitoring the Future survey asked teens about them. The CDC has estimated that during 2013, about 4.5 percent of high school students had tried e-cigarettes during the prior month, a figure that's tripled since 2011. Some research has suggested e-cigarettes may act as a gateway to regular smoking for teens.
The CDC reported last week that 10 states permit the sale of e-cigarettes to minors. The Food and Drug Administration has proposed regulating e-cigarettes, including banning sales to minors; there is no timetable for final rules.