A new report:
Increasing Prevalence of Parent-Reported Attention-Deficit/Hyperactivity Disorder Among Children — United States, 2003 and 2007 shows the prevalence of ADHD increasing especially among boys.

The findings in this report demonstrate a substantial increase in the percentage of children ever diagnosed with ADHD (according to parent report), with nearly one in 10 children aged 4–17 years diagnosed with ADHD by 2007. The overall estimate for the prevalence of children with a history of ADHD diagnosis in 2007 was higher than a recent estimate (8.4% of children aged 6–17 years) based on annual data from the 2004–2006 National Health Interview Survey (NHIS) (2). The NHIS report documented an average annual increase in diagnosed ADHD (ever) of 3% from 1997 to 2006; this present report documents a greater average annual increase (5.5%) over a slightly later period (2003–2007). The differences might reflect the inclusion of more recent data in this present report or differences in survey methods.