Adults who suspect they may be autistic or have ADHD show corresponding neurodevelopmental polygenic effects

The study examined genetic and phenotypic profiles of UK Biobank adults who suspect they are autistic or have ADHD compared to diagnosed and undiagnosed individuals. The research included 154,926 participants with an autism questionnaire and 161,623 participants with an ADHD questionnaire. Results showed that adults with suspected autism (n=6,797) or suspected ADHD (n=3,611) had genetic correlations with external GWAS autism and ADHD that were not statistically lower than 1. Polygenic scores for most neurodevelopmental and mental health conditions were elevated in both suspected and diagnosed groups compared to the no-diagnosis group. However, differences between suspected and diagnosed groups were found in the rates of co-occurring mental health conditions and neurodevelopmental trait scores, which were highest in the diagnosed group. The research suggests that factors beyond underlying polygenic profiles determine who seeks and receives a diagnosis.