In a first-of-its-kind report, the U.S. Centers for Disease Control and Prevention says that as many as 1 in 5 American children has a mental disorder including autism.

The report released Thursday focuses on kids ages 3 to 17 between the years 2005 and 2011. It is said to be the most comprehensive federal look at children’s mental health issues to date.

Attention deficit hyperactivity disorder, or ADHD, was the most common diagnosis, with nearly 7 percent of kids affected. Meanwhile, behavioral or conduct problems touched 3.5 percent of children while 3 percent had anxiety and roughly 2 percent were diagnosed with depression, the CDC found.

The report is largely based on data collected through other surveys. Accordingly, it puts autism prevalence at 1.1 percent, though a more recent government survey released earlier this year suggests that number may in fact be 2 percent.

Overall, the CDC indicated that somewhere between 13 and 20 percent of U.S. children experience a mental disorder each year, with an estimated annual price tag of $247 billion.

“Millions of children in the U.S. have mental disorders that affect their overall health and present challenges for their loved ones,” said Tom Frieden, director of the CDC, in a statement. “We are working to both increase our understanding of these disorders, and help scale up programs and strategies to promote children’s mental health so that our children grow to lead productive, healthy lives.”