Research by the Indraprastha Institute of Information Technology Delhi highlights how subtle changes in pupil behaviour could help identify attention-related differences in children with ADHD, with medication showing promise in stabilising pupil responses.
A recent study published in Scientific Reports suggests that small changes in pupil response could offer clues about attention-related differences in children with attention-deficit/hyperactivity disorder, particularly when they are carrying out tasks that demand focus and memory. Researchers found that children with ADHD showed greater trial-to-trial variation in how their pupils reacted than children without neurodevelopmental disorders, pointing to a possible physiological marker of inconsistent attention.
The work, carried out by researchers at the Indraprastha Institute of Information Technology Delhi, re-analysed data from eye-tracking tests involving 50 children aged 10 to 12. The group included 28 children with the combined type of ADHD and 22 children without the condition. According to the study, children with ADHD who were not taking medication showed about 23% more variation in pupil responses between attempts than the control group.
That greater instability was also linked with weaker performance. The researchers reported that children whose pupil responses varied more widely were generally less accurate during the task, suggesting a connection between pupil behaviour and how consistently they engaged with the exercise. Even so, the authors cautioned that changes in pupil movement do not automatically mean a child has an attention disorder, and may instead reflect shifts in alertness or task engagement.
The study also examined the effect of methylphenidate, a common ADHD medication. Children with ADHD completed the test twice: once after stopping the drug for 24 hours and again after taking their usual dose. After medication, their pupil responses became stronger during the task, the variation between trials fell and the timing and shape of the responses looked more like those seen in children without ADHD.
The findings build on earlier research that has explored pupil size and eye movement as possible ADHD markers. A Scientific Reports paper from 2017 also found differences in pupil responses between children with ADHD and neurotypical controls, while a 2023 study reported that eye-movement and pupil-dilation measures could help predict ADHD symptoms over time. More recent work has continued to examine whether pupil dynamics may reveal underlying attention and arousal patterns, but researchers say the field is still at an early stage and that pupil measurements are not ready for clinical diagnosis.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
