(AP) -- More teens are turning to pot and see it as less of a risk at the same time alcohol use among the same age group has dipped to historic lows, according to an annual national survey of drug use released Wednesday.
The findings were based on a survey of 47,000 eighth-, 10th- and 12th-graders conducted by the University of Michigan for the National Institute on Drug Abuse.
One of every 15 high school seniors reported smoking pot on a daily or near daily basis, the highest rate since 1981.
One of every nine high school seniors reported using synthetic marijuana, sometimes called Spice or K2, within the previous 12 months.
Marijuana use rose among 10th- and 12th-graders, the study said. None of the changes was large enough to be statistically significant, "but they all continue the pattern of a gradual rise," the study said. There was a "non-significant decrease" in the percentage of eighth-graders who reported using pot within the past year.
The percentage of teens saying they see "great risk" in using marijuana generally has dropped in recent years.
"One thing we've learned over the years is that when young people come to see a drug as dangerous, they're less likely to use it," Lloyd Johnston, the study's principal investigator, said in a telephone interview with The Associated Press. "That helps to explain why marijuana right now is rising, because the proportion of kids who see it as dangerous has been declining."
The study said marijuana use among teens rose in 2011 for the fourth straight year after considerable decline in the preceding decade.
The survey found 36.4 percent of 12th-graders reported using marijuana in the past year, compared to 31.7 percent in the 2007 survey. Usage was at 28.8 percent for 10th-graders and 12.5 percent for eighth-graders within the previous 12 months, according to the 2011 survey.
The synthetic drug survey question was asked for the first time this year. Fake marijuana, sometimes sold in drug paraphernalia shops and on the Internet as incense, contains organic leaves coated with chemicals that provide a marijuana-like high when smoked.
A Drug Enforcement Administration emergency order banning the sale of five chemicals used in herbal blends to make synthetic marijuana took effect March 1. The synthetics are among the many that would be banned under a bill passed in the U.S. House earlier this month. Many states also have their own laws banning the sale of synthetic marijuana.
Researchers say next year's survey will reveal more about the effectiveness of the control measures, since much of this year's survey covered a response period before the federal action took effect.
White House drug czar Gil Kerlikowske called on parents to get involved to help stop the use of synthetic marijuana.
"It's not in the vocabulary of parents, and they need to be aware of it so that when they have that conversation about substance abuse that they are knowledgeable and they talk about this," he told the AP.
Alcohol use continued a trend of decline dating to the 1980s and hit a historic low for the survey, which began in the 1970s for 12th-graders. Forty percent of 12th-graders reported drinking in the previous 30 days during the 2011 survey, compared to 54 percent in 1991. Drinking also declined significantly at lower grade levels.
Other drugs showing some evidence of decline in use this year include cocaine, crack cocaine and inhalants.
The Monitoring the Future survey also shows that a decline in teen cigarette smoking resumed this year. The number of those who reported smoking in the previous 30 days for the three grades combined was 11.7 percent, compared to 12.8 percent in 2010.
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The survey can be found at http://www.monitoringthefuture.org