# Scientists link ADHD genetic scores to disrupted neural timing > Source: > Published: 2026-06-14 11:00:46+00:00 Genetic likelihood for attention-deficit/hyperactivity disorder directly predicts irregular timing in the brain waves responsible for focus and goal-directed behavior. This objective link between a person’s genetic profile and their neural activity provides a measurable target for understanding how the condition develops. The research was recently published in the journal * Translational Psychiatry*. Cognitive control is the mental process that allows humans to prioritize relevant information and ignore distractions to achieve specific goals. When people struggle with this ability, they often have a harder time keeping their attention focused in everyday environments. Difficulties with cognitive control are common in neurodevelopmental conditions like attention-deficit/hyperactivity disorder, or ADHD, as well as autism. To measure this mental process, researchers look at electrical signals in the brain known as midfrontal theta activity. These are brain waves occurring at a frequency of four to eight cycles per second in the frontal part of the head. These brain waves act as a neural conductor, coordinating the activity of different brain regions when a person needs to navigate conflicting information. In people with ADHD, the timing of these brain waves is often irregular. This lack of precise temporal coordination usually translates to inconsistent reaction times during tasks. A person might respond very quickly on one attempt but much more slowly on the next attempt. This behavioral inconsistency is a recognized characteristic of ADHD across many different age groups. Researchers wanted to know if a person’s genetic profile could predict these specific irregularities in brain wave timing. They relied on a tool called a polygenic score, which combines information from millions of small genetic variations across the genome into a single number. This score estimates an individual’s overall genetic likelihood of developing a specific condition based on traits inherited from their parents. By looking at polygenic scores, researchers can bridge the gap between abstract genetic risk and actual physical measurements of brain function. Brain wave measurements that show clear family inheritance patterns can serve as a bridge connecting a person’s DNA to their observable behaviors. Understanding these connections helps experts see exactly how genetic risks manifest as physical changes in the brain. Ümit Aydin, a researcher at the University of Reading and King’s College London, led the investigation. Gráinne McLoughlin, a cognitive neuroscience researcher at King’s College London, served as the senior author on the project. The team wanted to test whether polygenic scores for ADHD and autism could predict erratic brain wave timing and inconsistent reaction times. The research team recruited 454 young adults with an average age of 22 to participate in the project. These individuals had previously provided DNA samples for an ongoing registry called the Twins Early Development Study. The participant group included individuals diagnosed with ADHD, individuals diagnosed with autism, and people with no such conditions. [Add PsyPost to your preferred sources](https://www.google.com/preferences/source?q=psypost.org) To measure cognitive control, the researchers asked participants to complete an arrow-based computer exercise called a flanker task. Participants looked at a screen and pressed a left or right button indicating the direction of a central arrow. To make the exercise challenging, the central arrow was flanked by other arrows pointing in the opposite direction. The human brain must exert cognitive control to ignore the misleading flanker arrows and focus only on the central target. While the participants completed this exercise, the researchers recorded their brain waves using an electroencephalogram, or EEG. Participants wore a cap fitted with 64 sensors that picked up the electrical signals passing through their scalp. The team focused specifically on the timing consistency of the theta brain waves across multiple trials. They looked at the moments where participants correctly identified the arrow direction despite the confusing visual interference. Separately, the researchers calculated polygenic scores for ADHD and autism for each participant using their previously collected DNA. The team then ran statistical models to see if these genetic scores matched up with the brain wave patterns and reaction times recorded during the computer exercise. They adjusted their mathematical models to account for the participants’ ages, sexes, and familial relationships. To ensure their brain wave measurements were completely reliable, they also brought a smaller group of 21 participants back for a second session roughly a week later. The analysis showed that participants with a higher polygenic score for ADHD had more irregular timing in their midfrontal theta brain waves. This irregular neural timing appeared almost entirely independent of demographic factors. The genetic score for ADHD directly predicted the specific neural signature associated with poor cognitive control. McLoughlin explained the importance of connecting the genetic markers to physical brain activity. “For the first time, we’ve linked genetic likelihood for ADHD directly to disrupted neural timing. The brain’s theta rhythm acts like a conductor coordinating cognitive processes – in ADHD, that conductor’s timing is irregular and we have now shown that this irregularity has genetic origins linked to ADHD,” she said. Having a physical measurement of this mental process could help experts evaluate future interventions. Finding an easily quantifiable brain signal gives medical professionals a concrete way to assess how well different therapies might work. As McLoughlin noted, “This matters because it gives us an objective neural target for developing and testing treatments.” The genetic scores for autism did not predict the same irregular brain wave timing or reaction time variability. The researchers found no statistical association between the autism polygenic scores and the brain wave measurements. Despite the clear link between ADHD genetic scores and brain wave timing, the study had some limitations. The genetic scores did not statistically predict the behavioral inconsistency in participants’ actual physical reaction times. The research team noted that their participant pool might have been too small to detect the smaller genetic effects associated with reaction speeds. The demographic makeup of the participant pool also limits how broadly the conclusions can be applied. All 454 participants were of white ethnic origin. Future studies will need to include individuals from diverse ethnic backgrounds to see if the same genetic associations hold true across different global populations. Additionally, polygenic scores only account for very common genetic variations. They do not capture rare genetic changes or environmental influences, which also play a major role in how ADHD develops. Because of these missing pieces, polygenic scores provide only a partial picture of a person’s total genetic risk. Some of the specific genes included in the ADHD polygenic score are known to affect brain development and cell connections. One particular genetic location identified in the score helps regulate dopamine in the brain. This is highly relevant because many common medications used to treat ADHD work by targeting the brain’s dopamine systems. Moving forward, the researchers plan to use larger sample sizes to explore exactly how these genetic variations disrupt the brain’s internal timing networks. They hope to map out the exact biological pathways that translate a person’s genetic code into the brain wave irregularities seen in ADHD. By tracking these pathways, experts could eventually design personalized treatment strategies based on a patient’s unique genetic and neural profile. The study, “[ADHD polygenic risk predicts neural signatures of cognitive control: Evidence from midfrontal theta dynamics](https://doi.org/10.1038/s41398-026-03938-2),” was authored by Ümit Aydin, Ziye Wang, Máté Gyurkovics, Amy Tong, Grace Cullen, Sumayyah Ahmed, Jason Palmer, and Gráinne McLoughlin.