Marijuana use by teens has increased since 2005.
But a new study out of the University of Oregon finds no evidence that legalizing medical marijuana has contributed to the increase.
Three economists from the U of O, Montana State University and University of Colorado Denver, looked at data from the "Youth Risky Behavior Survey." The survey is conducted by the Centers for Disease Control and Prevention.
In a statement on the U of O website, Assistant professor Benjamin Hansen says researchers looked for a correlation between the passage of medical marijuana laws in a state, and an increase in illegal drug use among high school students.
"We find little evidence that teen drug use increases with the passage of a medical marijuana law within a state," said Hansen.
The findings stand in contrast to statements by the White House's Office of National Drug Control Policy. The administration says legalization threatens public health by increasing the availability of drugs, and that it poses a significant health and safety risk to all Americans, especially young people.
Seventeen states and the District of Columbia now have medical marijuana laws.