In 2010, American teens’ past-month use of marijuana rose high enough to eclipse their use of cigarettes, according to a national report on teen substance abuse — a finding that the White House and public-health officials blamed in part on drug-legalization efforts.
The growing popularity of marijuana — possibly fueled by the idea that “marijuana is medicine” — alarms national leaders who point to the drug’s side effects and its role as a “gateway drug.”
Not only does marijuana use adversely affect learning, judgment and motor skills in developing minds, “but research tells us that about one in six people who start using it as adolescents become addicted,” said Dr. Nora D. Volkow, director of the National Institute on Drug Abuse (NIDA).
NIDA funds the Monitoring the Future survey, which was released Tuesday.
“No young person in today’s competitive world is going to be helped by using marijuana” or other illicit drugs, said R. Gil Kerlikowske, director of the Office of National Drug Control Policy.
“Mixed messages about drug legalization, particularly marijuana, may be to blame” for increases in drug use, the White House’s “drug czar” said.
According to the survey, which is based on interviews with more than 46,000 students, 21.4 percent of 12th-graders, 16.7 percent of 10th-graders and 8.0 percent of eighth-graders said they had used marijuana or hashish in the previous 30 days. These figures surpass past-month cigarette use, which was 19.2 percent of 12th-graders, 13.6 percent of 10th-graders and 7.1 percent of eighth-graders.
Anti-smoking campaigns, reduction of cigarette advertising to youths and rising cigarette prices helped reduce youthful use of smoking, said Lloyd Johnston, principal investigator of Monitoring the Future.
However, the messages about marijuana have been anything but clear.
In November, California came close to legalizing marijuana for adults when more than 46 percent of the electorate voted in favor of Proposition 19. Backers of the measure were elated with their near-success and have promised to try again in 2012.
Numerous cities and states, meanwhile, have legalized the medical uses of marijuana, and the pro-legalization position, whether for medical use or for any purpose, is an increasingly mainstream part of political discourse.
In the meantime, marijuana use increased in 2010 over 2009 by every yardstick — daily, in the past 30 days, in the past year or ever — and at all three measured grade levels.
The news about rising youth use of marijuana reinforces the idea that it’s time for a national conversation about marijuana legalization, said Mike Meno, communications director for the Marijuana Policy Project.
“Nobody wants young people using marijuana; that’s a common goal,” he said.
Although federal policy makes reducing youth use of marijuana a priority, Tuesday’s numbers and those in previous years show that the policy “failed absolutely” to do that, Mr. Meno said.
If marijuana were legal, it could be taxed and regulated to bar its sale to youths, as happens with alcohol and tobacco, he added. “Drug dealers don’t check ID.”
The Obama administration is aggressively addressing the threat of drug use and needs parents to talk with their children about the risks and harms of illegal drug use, Mr. Kerlikowske said.
An official at NIDA added that her agency is offering a wealth of Web-based materials for teens, including the “Sara Bellum” blog about drugs and “chat sessions” with scientists who answer teens’ questions about drugs.
Marijuana has been the most widely used illicit drug in the 35-year history of the Monitoring the Future survey, though it remains dwarfed by the use of alcohol. Tobacco is still more popular among teens by some of the survey’s numerous yardsticks.
Annual marijuana use reached its historical peak among 12th-graders in 1979, when 51 percent of high school seniors said they had smoked pot at least once within the previous year. It bottomed out in 1992, with 21.9 percent annual use, and has been in the 30s for more than 15 years. Unlike marijuana, the use of alcohol and tobacco have declined nearly continuously since the 1990s.
Because marijuana is more prevalent than any other illicit drug, trends in its use tend to drive the index of any illicit drug use, the survey said.
Other highlights of the report:
• Compared with 2009, rates fell regarding teen abuse of the prescription drug Vicodin, cocaine, binge drinking and use of “flavored alcoholic beverages.”
• The usage rate of the “club drug” Ecstasy rose in all three grades. This suggests that the dangerous drug is experiencing a resurgence, especially among younger teens.
• Rates of many illicit drugs, such as methamphetamine, crack cocaine and heroin stayed at low levels. Mr. Johnston said the use of inhalants has not risen as feared, and the abuse of cough and cold medicines also has stalled.
Thus the most worrisome aspects of the 2010 data were the upticks in marijuana use and weakening attitudes about the harmfulness or disapproval of pot.
“We should examine the extent to which the debate over medical marijuana and marijuana for adults is affecting teens’ perceptions of risk,” Dr. Volkow said. Teens need to know that “marijuana use can harm their short-term performance, as well as their long-term potential.”