The first genome-wide study of sulcal depth shows that it is highly genetically discoverable, associated with neurodevelopment.

Personality and cognitive function are heritable mental traits whose genetic foundations may be distributed across interconnected brain functions. Previous studies have typically treated these complex mental traits as distinct constructs. We applied the "pleiotropy-informed" multivariate omnibus statistical test to genome-wide association studies (GWAS) of 35 measures of neuroticism and cognitive function from the UK Biobank (n=336,993). We identified 431 significantly associated loci with evidence of abundant pleiotropy across personality and cognitive function domains. Functional characterisation implicated genes with significant tissue-specific expression in all tested brain tissues and brain-specific gene-sets. We conditioned independent GWASs of the Big 5 personality traits and cognitive function on our multivariate findings, boosting genetic discovery in other personality traits and improving polygenic prediction. These findings advance our understanding of the polygenic architecture of these complex mental traits, indicating a prominence of pleiotropic genetic effects across higher-order domains of mental function such as personality and cognitive function.