A novel method to diagnose attention deficit hyperactivity disorder (ADHD) may be in plain sight.
In a new study from Tel Aviv University published in Vision Research, involuntary eye movements accurately reflect the presence of ADHD, as well as the benefits of stimulants used to treat the disorder.
“We had two objectives going into this research,” said Moshe Fried, Ph.D., who as an adult was himself diagnosed with ADHD.
“The first was to provide a new diagnostic tool for ADHD, and the second was to test whether ADHD medication really works — and we found that it does.
There was a significant difference between the two groups, and between the two sets of tests taken by ADHD participants un-medicated and later medicated.”
ADHD is the most commonly diagnosed — and misdiagnosed — behavioral disorder in children in America.
There is no reliable physiological marker to diagnose ADHD. Physicians generally diagnose the disorder by recording a medical and social history of the patient and the family, discussing possible symptoms and observing the patient’s behavior.
However, an incorrect diagnosis can lead to overmedication with Ritalin (methylphenidate).
In the study, researchers used an eye-tracking system to monitor the involuntary eye movements of two groups of 22 adults taking an ADHD diagnostic computer test called the Test of Variables of Attention (TOVA).
The exercise, which lasted 22 minutes, was repeated twice by each participant. The first group of participants, diagnosed with ADHD, initially took the test un-medicated and then took it again under the influence of methylphenidate.
A second group, not diagnosed with ADHD, constituted the control group.
Researchers found a direct correlation between ADHD and the inability to suppress eye movement in the anticipation of visual stimuli.
The research also reflected improved performance by participants taking methylphenidate, which normalized the suppression of involuntary eye movements to the average level of the control group.
“This test is affordable and accessible, rendering it a practical and foolproof tool for medical professionals,” said Fried.
“With other tests, you can slip up, make ‘mistakes’ — intentionally or not. But our test cannot be fooled. Eye movements tracked in this test are involuntary, so they constitute a sound physiological marker of ADHD.
“Our study also reflected that methylphenidate does work. It is certainly not a placebo, as some have suggested.”
The researchers are currently conducting more extensive trials on larger control groups to further explore applications of the test.