A seventh-grade girl suffers such persistent teasing by her classmates that she leaves school — and goes on to become a teen acting and singing sensation. Sound like the only-in-Hollywood plot to a Disney Channel special?

As it turns out, that plucky heroine is very real:  Demi Lovato, who appeared in the Disney sit-com Sonny With a Chance and TV movies, Camp Rock, and Camp Rock 2 and has produced several successful music albums.  Now Lovato’s using her special status as a former victim of bullying turned star and musician to raise awareness of the issue among teenagers.

As the spokesperson for Teens Against Bullying, a website sponsored by the PACER Center, an advocacy group for young people with disabilities, Lovato appears on the site in black fingernail polish and pink lip-gloss to share her own tale of harassment hell.

Created by and for adolescents, the website features real-life stories, teen-produced videos, and blogs, as well as an online toolbox of resources for students and schools to address bullying.

How pervasive is the problem? According to the National Association of School Psychologists, more than 160,000 U.S. children skip school daily because they feel threatened by another student. The consequences for bullying victims can be long lasting and devastating: poor grades, low self-esteem, depression, even suicide.

“People say, ‘Sticks and stones may break your bones, but names can never hurt you,’ but that’s not true,” writes Lovato on the PACER site. “Things were said to me that I still haven’t forgotten.”

By making bullying prevention not just a cause but a cool cause, PACER hopes to empower teens to create more-inclusive school environments where everyone feels safe and welcome. “When bullying is addressed,” says Paula Goldberg, PACER’s executive director, “communities will see more students with higher self-esteem, better school attendance, less physical and mental stress, and better school performance.”

And the culture at large, which in many ways glamorizes mean girls (and boys) of all ages, may undergo a shift and celebrate the underdog for a change. As one student writes on Teens Against Bullying about overcoming feelings of inadequacy, “Now when I think back to the time I cried for being different, I would cry if this uniqueness was taken away from me.”