In the first study of its kind, the U.S. Centers for Disease Control and Prevention found that up to one in five kids has a mental health disorder. That's about 20 percent of kids ages 3 to 17, and it costs about $247 billion yearly in terms of medical bills, special ed and the juvenile justice system. Spanning the years 1994 to 2011, the study also found that mental health disorders are rising in frequency among kids.
A mental disorder is defined as a "serious deviation from expected cognitive, social and emotional development," according to the report. The most frequently seen disorder is ADHD, which touches 6.8 percent of all children. Also on the list: behavioral conduct problems (3.5 percent), anxiety like fears and phobias (3 percent), depression (2.1 percent) and autism spectrum disorders (1.1 percent). Researchers hypothesized that change in diagnostic criteria could be just as big a factor in the seemingly rising rates as actual increased prevalence.