That Facebook is hugely distracting is hardly stop-the-presses kind of news, but parents might be dismayed to learn that the social-media site can hobble learning and make kids less healthy and more depressed.

Research has found that students in middle school, high school and college who checked Facebook at least once during a 15-minute study period got lower grades. Other studies have discovered that teens who use Facebook tend to have more narcissistic tendencies, while young adults who are active on the site display other psychological disorders. And daily use of media and technology — what teen doesn't use tech each day? — makes kids more prone to anxiety and depression.