Could attention deficit hyperactivity disorder (ADHD) be a spectrum disorder? It might be, according to research from Cardiff University School of Medicine and the University of Bristol. The researchers analyzed groups of genes related to ADHD risk. They discovered that attention, hyperactivity/impulsiveness, and language skills—key components of ADHD—exist on a spectrum. These ADHD symptoms are variously associated with different clusters of genes. The study could redefine how we view and treat ADHD.
The researchers used genetic data from patients with ADHD and data from the Avon Longitudinal Study of Parents and Children (ALSPAC). ALSPAC is an ongoing study that tracks a cohort of children born in the early 1990s in England. In the present study, the researchers used a sample of over 8,200 from ALSPAC. Using the genetic data, the researchers created composite scores based on groups of genes. These polygenic scores tally the genetic risk of ADHD.
Individuals with a higher polygenic risk for ADHD were more likely to have stronger ADHD symptoms related to hyperactivity/impulsiveness and attention at ages 7 and 10. A higher polygenic risk was also related to weaker social language skills. The analysis revealed that genetic factors in individuals with ADHD predicted higher levels of developmental difficulties.
These findings challenge the traditional view of ADHD. Redefining ADHD as a spectrum could link the disorder more closely to autism, as many recent studies have.
By being able to examine the risk factors for ADHD on a genetic level, clinicians may be able to identify the children most likely to struggle with attention. This could lead to targeted interventions that help children with ADHD perform better academically.
The results “suggest that the same sets of genetic risks contribute to different aspects of child development which are characteristic features of neurodevelopmental disorders such as ADHD and autism spectrum disorder,” explained first author of the study Joanna Martin.
This research is published in the journal Biological Psychiatry.