Our finding that approximately 11,500 (s.e. = 607) causal variants account for 90% of the SNP-based heritability of OCD suggests that OCD is more polygenic than other complex traits such as height (ncausal = 4,000), schizophrenia (ncausal = 9,600) and ADHD (ncausal = 5,600), but less polygenic than major depression (ncausal = 14,500) and educational attainment (ncausal = 13,200)50.
