JAMA - USA

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent disorder
estimated to affect 3% to 9% of school-aged children and approximately
4% of adults ...

.... 13-14 The Brown attention-deficit disorder and Wender-Reimherr scales
are also used commonly to diagnose ADHD (and comorbidity) in adults.
14.
....
http://jama.ama-assn.org/cgi/content/full/292/5/619