Are there gender differences in ADHD?

More boys are diagnosed with ADHD than girls with recent estimates of ratios ranging from 2:1 to 6:1. Experts have hypothesized the following as explanation for the observed gender difference:

• A referral bias may exist that under identifies ADHD in girls.
• The global deficits that have been documented in boys with ADHD, such as having a difficult time processing information, holding information on line, estimating time, and stopping a behavior once started may not extrapolate to girls.
• Some research suggests that girls who are diagnosed with ADHD are largely ignored because it is believed that they are not as impaired.

Source: J. Rucklidge (2009). “Neuropsychological functioning in ADHD: Are girls different from boys?”