New ADHD test uses EEGs
The FDA has approved the NEBA System to help diagnose ADHD. Using EEGs, the test compares the ratio of theta to beta waves. In the past, the ratio has been shown to be greater in kids with ADHD. The test takes 15-20 minutes and is noninvasive.
http://www.medicalnewstoday.com/articles/263440.php