High school students who spend the most time texting, using social networking sites, or both, are at highest risk for troublesome behaviours, like smoking, drug and alcohol abuse, absenteeism, eating disorders and depression, the New York Times reports. In a new study, researchers from Case Western Reserve University surveyed more than 4,000 students at 20 urban high schools in Ohio. About one-fifth sent at least 120 texts a day, and one-tenth were on social networks for three hours or more. Four per cent did both, and they were at twice the risk of nonusers for fighting, smoking, binge drinking, missing school, sleeping in class, thinking about suicide, and becoming cyber victims. Those who used texts and social networks most frequently also listed their parents as most permissive.