Brendesha Tynes of the University of Illinois said teenagers are increasingly tethered to the Internet -- 93 percent of U.S. teens have online access -- and regardless of a victim's racial background, increased exposure to online racial discrimination was significantly related to increased depression.

"There's been a lot of publicity about cyber-bullying and teenagers protecting themselves from online predators, and justifiably so," Tynes said in a statement. "But people don't know much about online racial discrimination and its effects on adolescent emotional well-being."

Tynes and co-authors Michael T. Giang, David R. Williams and Geneene N. Thompson created a measure for race-related online victimization. The researchers discovered 71 percent of African-American adolescents, along with 71 percent of white and 67 percent of multiracial/other adolescents, experienced vicarious racial discrimination online at least once.

The study, published in the Journal of Adolescent Health, also found 29 percent of African-American adolescents and 20 percent of white and 42 percent of multiracial/other adolescents reported experiencing individual discrimination directed at them while online.