University of Minnesota Medical School researcher Iris Borowsky, M.D., Ph.D., and colleagues analyzed data collected by the National Longitudinal Study of Adolescent Health, a nationally representative sample of more than 20,000 youth in grades 7 through 12 during three separate study years. In the first set of interviews, nearly 15 percent of adolescents predicted they had a 50/50 chance or less of living to age 35.

The researchers found that those who engaged in risky behaviours such as illicit drug use, suicide attempts, fighting, or unsafe sexual activity in the first year were more likely in subsequent years to believe they would die at a young age.

Vice versa, those who predicted that they'd die young during the first interview were more likely in later years to begin engaging in these same risky behaviors and have poor health outcomes, the researchers found.

Notably, these teens were significantly more likely to be diagnosed with HIV/AIDS just six years later, regardless of their sexual preference.

"While conventional wisdom says that teens engage in risky behaviours because they feel invulnerable to harm, this study suggests that in some cases, teens take risks because they overestimate their vulnerability, specifically their risk of dying," Borowsky said.

"These youth may take risks because they feel hopeless and figure that not

much is at stake," Borowsky added.

Nearly 25 percent of youth living in households that receive public assistance and more than 29 percent of American-Indian, 26 percent of African-American, 21 percent of Hispanic, and 15 percent of Asian youth reported believing they would die young—compared to just 10 percent of their Caucasian peers.

"Our findings reinforce the importance of instilling a sense of hope and optimism in youth. Strong connections with parents, families, and schools, as well as positive media messages, are likely important factors in developing an optimistic outlook for young people," Borowsky said.

There was no significant relationship between perceived risk of dying before age 35 and actual death from all causes during the six-year study period.

The study has been published in the July issue of Paediatrics.