The percentage of teenagers who receive substanced abuse prevention messages from the media in the past year dropped from 83.2 percent in 2002, to 75.1 percent in 2011, according to a new government report.

Teens also received fewer school-based prevention messages, the Substance Abuse and Mental Health Services Administration (SAMHSA) found. Such messages reached 78.8 percent of teens in 2002, and 74.5 percent in 2011. An estimated 40 percent of teens did not talk with their parents in the past year about the dangers of substance abuse, Newswise reports.

A recent SAMHSA report found teen attitudes about the risk of substances such as alcohol and marijuana have changed in recent years. From 2002 to 2011, the percentage of teens who perceived great risk from heavy drinking increased from 38.2 percent to 40.7 percent. During that same time, there was a drop in binge drinking among teens, from 10.7 percent to 7.4 percent.

The report found the percentage of teens who perceived great risk from marijuana use once or twice a week dropped, from 54.6 percent in 2007, to 44.8 percent in 2011. Teens’ rate of past-month marijuana use increased during that time, from 6.7 percent to 7.9 percent.

“To prevent substance abuse among our adolescents, our young people have to know the facts about the real risks of substance abuse, and we’re not doing a very good job of that right now,” SAMHSA Administrator Pamela S. Hyde said in a news release. “It is time for all of us – the public health community, parents, teachers, caregivers, and peers – to double our efforts in educating our youth about substance use and engaging them in meaningful conversations about these issues, so that they can make safe and healthy decisions when offered alcohol or drugs.”