A biomarker on an electroencephalogram may help doctors make a more accurate diagnosis of attention deficit hyperactivity disorder (ADHD). A more accurate diagnosis can help determine which children have ADHD and which with another condition that produces similar symptoms.
The biomarker is called the theta/beta ratio and a study has found that it can help improve the accuracy of an ADHD diagnosis. An electroencephalogram, also called an EEG, measures the electrical activity in the brain and creates a recording of the activity as a series of brain waves. Two of the waves are called theta and beta. The study studied adding an assessment of the theta/beta ratio to the clinical assessment of the patients by one or more physicians.
Researchers conducted a prospective clinical study at 13 medical centers. They analyzed evaluation data from 275 children and teens that were undergoing neurological testing because of problems with attention and behavior. EEG readings were collected and a physician made a diagnosis based on his or her clinical assessment. This diagnosis was compared to a consensus diagnosis made by an independent team consisting of a psychiatrist, psychologist, and neurodevelopmental pediatrician.
Of these 275 patients, 209 were given a diagnosis of ADHD by the original physician, but for 93 of these, the outside team thought that they might not have ADHD. This would be an overdiagnosis rate of 34%.
A measurement of the theta/beta ratio was integrated into the original information. Of those 93 patients, 85 of them (91%) were also found to have a relatively lower theta/beta ratio on their EEG. Further, adding the theta/beta ratio method agreed with the outside team's diagnosis 97% of the time. The patients who had a relatively lower theta/beta ratio were more likely to have other conditions that could causes symptoms similar to ADHD.
The study concluded that adding or integrating the theta/beta ratio information with a physician's ADHD evaluation could help improve the diagnostic accuracy from 61% to 88%.
The study was published in the journal Brain and Behavior.
