Retina Study Paves the Way for Physical ADHD Symptom Test
Posted on May 31, 2016 Examining patients’ retinas may one day help doctors diagnose ADHD, says a new study presented at the American Psychiatric Association (APA) 2016 Annual Meeting. According to the study’s findings, the retinas of patients with ADHD exhibit more “background noise” – or neural activity that isn’t driven by a specific stimulus […]
Posted on May 31, 2016
Examining patients’ retinas may one day help doctors diagnose ADHD, says a new study presented at the American Psychiatric Association (APA) 2016 Annual Meeting. According to the study’s findings, the retinas of patients with ADHD exhibit more “background noise” – or neural activity that isn’t driven by a specific stimulus – than do those of non-ADHD patients. Effective ADHD treatment decreases this background noise to normal levels – suggesting that medication helps control the neuronal activity that contributes to inattention or hyperactivity.
Using a process known as pattern electroretinography – more commonly known as PERG – researchers from Saarland University in Germany examined the retinas of 20 adults with ADHD and 20 neurotypical control subjects. PERG measures activity in the retina’s nerve centers using electrophysiology; in this case, researchers measured patients’ responses to a checkerboard visual stimulus. Patients with ADHD had significantly more “background noise” than did non-ADHD patients, a measurement that correlated significantly with the severity of each individual’s inattentive symptoms (as measured by the Conners’ Comprehensive Behavior Rating Scales). After a round of methylphenidate, the patients with ADHD were tested again. When ADHD symptoms were controlled by medication, levels of background noise in the patients’ retinas normalized – indicating a connection with ADHD.
The results confirm those of a 2013 study, also from Germany, that was partially conducted by the same team. Both studies were small, but may lay the groundwork for a new diagnostic tool for ADHD – a condition for which no definitive physical test currently exists.
“There is growing evidence for a special relevance of background noise, or non-stimulus-driven neural activity, in ADHD,” said Emanuel Bubl, MD, the lead researcher on both studies. “Findings from animal studies as well as human research supports this line of thought, and our results directly support findings from basic research, which is intriguing.”
PERG is well established as a diagnostic tool in ophthalmology, but its use in psychiatry is still in the early stages. Still, Dr. Bubl’s replicated results may warrant further research on the subject. “As with other findings,” he said, “if we get more evidence for an elevated retinal noise in ADHD, I think this is a promising tool.”