Nana Matoba, a postdoc in the lab, led a study to evaluate whether brain traits satisfy one aspect of being an endophenotype for neuropsychiatric disorders. That is, are brain structure traits “closer to the underlying biology” than heterogeneous and behaviorally defined neuropsychiatric disorders? We evaluated this by comparing polygenicity, the total number of variants that are associated with a disorder, and discoverability, the distribution of effect sizes for a trait. An endophenotype is hypothesized to have reduced polygenicity and increased discoverability compared to a disorder. For some brain structure traits, like cortical surface area, relative to aggregated estimates across multiple neuropsychiatric disorders, we provide evidence to support brain structure traits as satisfying this aspect of an endophenotype. You can read more about this here.