That's what the data say, at least. Health care spending for 14- to 18-year-olds has grown faster than any other age group with private coverage:

Source: Health Care Cost Institute

This comes from a new Health Care Cost Institute report, which has access to huge troves of private health insurance claims data. Across age groups, most of the cost growth had to do with rising prices. The cost of a surgical admission rose 35 percent over the four years studied, hitting $35,496 to 2010.

Among teenagers, however, there was a separate factor also driving up spending: The increased use of mental health services. In 2010, the average teenager was prescribed 1.2 central nervous system drugs, which treat conditions like depression and attention-deficit hyperactivity disorder.

"The average mental health and substance abuse facility fee was $8,002 in 2010 — an increase of 20.6 percent from 2007," the report finds. "During this period, there was a 6.8 percent increase in the intensity of services provided."

Overall, teenagers with private insurance use 10.4 percent more central nervous system drugs than they did four years ago.