BARSTOW Barstow High School Principal Derrick Delton has good reason to be concerned about teen marijuana use. To him, using the drug makes students' motivation wane, they fall behind in credits and all that puts them at risk of dropping out of school, he said.

A new national study released earlier this month by the Partnership at showed that one in 10 teens are "heavy" marijuana users smoking at least 20 times a month. This represents an 80 percent increase in "heavy" teen users from 2008.

The study also showed that almost half of all teenagers reported using the drug at least once, while one in three teenagers use on a monthly basis. The study analyzed data taken from 3,322 teens in grades 9-12 and is nationally projectable with a 3 percent margin of error.

At Barstow High, 10 students have been expelled or suspended for drug-related offenses since August 2011, Delton said. In the school year before, the school cited 21 students for drug-related offenses.

Delton said he's noticed marijuana use in teens is more prevalent, and also more acceptable among them.

"When I was growing up it was bad to smoke," Delton said. "It was like, 'Stay away from those kids.' But now it's almost like a normal thing."

Social disapproval of marijuana among teens remained the same, the study showed, with 61 percent of teens saying they disapprove of their peers using marijuana. The data also found an erosion of anti-marijuana attitudes among teens, with only about half of teens saying they see "great risk" in using marijuana, down significantly from 61 percent in 2005.

"I think that the numbers probably aren't much higher in reality," Brandon Ness posted on the Desert Dispatch Facebook wall. "I think the high school aged students are just more comfortable with the idea of admitting they smoke marijuana."

Delton said he feels the increase is a result from the widespread media exposure of drugs. As students learn about drugs on TV or through social media, they become more accustomed to it, he said.

On the Desert Dispatch Facebook wall, Candace Younger wrote she learned about drugs in the sixth grade from D.A.R.E., a program that teaches about drugs and alcohol in an effort to reduce the use in teens.

"I blame the drug prevention programs for peaking interest," Younger wrote. "If I had never had D.A.R.E., I probably would have never tried anything until I was much older."

For more information or to view the study visit