Synthetic drugs, such as K2, mimic the effects of marijuana.

Almost one in nine high school seniors have gotten high in the past year on synthetic drugs, such as “K2” or “Spice,” second only to the number of teens who have used marijuana, according to a new survey.

“Monitoring the Future,” the nation’s most comprehensive survey of teenage drug use, found 11.4% of the high school seniors had used the synthetic substances, often packed as potpourri or herbal incense and sold in convenience stores, which mimic the effects of marijuana.

“It is astounding,” said Rep. Tom Latham, R-Iowa. “I don’t think they have any idea how dangerous these synthetic drugs are.”

Latham co-sponsored a bill to outlaw 16 synthetic compounds that mimic marijuana and 15 synthetic hallucinogens after an Indianola teen shot himself after taking K2 in July 2010. Latham’s bill passed last week. A Senate bill, sponsored by Sen. Chuck Grassley, R-Iowa, is awaiting action by the full Senate.

K2 and Spice emerged as a problem in 2008, and their popularity appears to be rising. Poison control centers handled 5,741 calls about the drugs in the first 10 months of 2011, nearly double the 2,915 calls received in all of 2010, according to the American Association of Poison Control Centers. People who smoke the chemical-coated herbs may experience euphoria, but bad reactions are common, including convulsions, anxiety attacks, dangerously elevated heart rates, vomiting and suicidal thoughts.

Federal officials became so alarmed that the Drug Enforcement Administration used its emergency powers in March to outlaw the substances. More than 40 states have also passed laws banning them.

“The next survey we do in spring 2012 will tell us a lot about how this ban has worked,” said Lloyd Johnston, the survey’s principal investigator.

Marijuana remains the most popular drug among teens. Marijuana use increased for the fourth year in a row after a decade of decline. Nearly 7% of high school seniors report smoking marijuana daily, the survey found.

“It’s the highest rate we’ve seen in 30 years, so something is going on,” Johnston said. He added that growing numbers of teens don’t see marijuana as dangerous.

“That’s a very bad indicator,” said Nora Volkow, director of the National Institute on Drug Abuse. “Either we do something to change that, or we will continue to see increases.”

Gil Kerlikowske, director of the White House Office on National Drug Policy, said state legalization of marijuana for medical use is influencing teens.

“We’re sending young people the wrong message when we call it medicine,” he said.

Half of high school seniors reported having tried an illicit drug at some time, 40% reported using one or more drugs in the past year, and a quarter said they had used one or more drugs in the past month, the survey found. Among 10th-graders, 38% said they had tried an illicit drug.

Tobacco and alcohol use are at their lowest levels since the survey began in 1975, Johnston said. “Kids consider smoking (cigarettes) to be dangerous. They aren’t even trying it,” he said.

The survey, conducted by the University of Michigan, questions 47,000 students in the eighth, 10th and 12th grades in 400 public and private schools around the nation. It is sponsored by the National Institute on Drug Abuse and the National Institutes of Health.

Via USA Today