AUGUSTA — A recent survey of Maine youth suggests marijuana use by high school and middle school students remains steady while the use of other drugs, including alcohol and tobacco, is in decline, according to a group hoping to defeat a referendum aimed at legalizing marijuana.

Scott Gagnon, director of Smart Approaches to Marijuana Maine, said that one in five youths in Maine report they have used marijuana in the past 30 days and 60 percent say they don’t believe there is any risk in regularly using marijuana, which is up 20 percent from 2009.

The data come from the biannual Maine Integrated Youth Health Survey. Policymakers and citizens should pay heed, Gagnon said.

“The fact that our marijuana numbers remain high while other youth drug use trends down should be a red flag for Mainers and lawmakers alike,” Gagnon said in a prepared statement. “The last thing we need is further normalization of drugs in the midst of a drug addiction crisis.”

The trend among Maine youths mirrors that of youths across the U.S., according to Dr. Kevin Sabet, president and CEO of Smart Approaches to Marijuana and a former White House drug policy adviser.

“Why is marijuana use not dropping like the use of other substances?” Sabet asked in a news release issued Wednesday. “The answer is likely the dramatic rise in marijuana commercialization and industrialization.”