CDC report shows High School students take fewer health risks than students in the 1990's, with some exceptions.
Here is the post on the Freakonomics blog.
Here is the CDC report.
Smoking is way down. Risky sex, suicide, and drinking is down. Helmet and seat belt use is better. Unfortunately, High School kids today are worse in reference to obesity, asthma, exercise, and using suncreen.
Dozens of additional behaviors are compared in the study, including bullying, school fights, eating habits, dating violence, and more.