Genetic correlation analysis of OCD with thirty-one phenotypes of interest was performed for the combined OCD sample and sex-stratified OCD samples using LD score regression (B. K. Bulik-Sullivan et al. 2015). Sex-stratified summary statistics for the following eight phenotypes were obtained (Supplementary Table 6): attention-deficit hyperactivity disorder (Martin, Walters, Demontis, Mattheisen, Lee, et al. 2017), post-traumatic stress disorder (Duncan et al. 2017), reproductive behavior (Barban et al. 2016), insomnia (Hammerschlag et al. 2017), educational attainment (Okbay, Beauchamp, et al. 2016), and alcohol consumption (Clarke et al. 2017; Schumann et al. 2016). In the absence of available sex-stratified summary statistics, sex-combined results were obtained for thirty-one phenotypes (Supplementary Table 7): Tourette Syndrome (Scharf et al. 2013; Yu et al. 2015), obsessive-compulsive symptoms (den Braber et al. 2016), post-traumatic stress disorder (Duncan et al. 2017), attention deficit hyperactivity disorder (Neale et al. 2010), autism (unpublished, available via Psychiatric Genomics Consortium), bipolar disorder (Psychiatric GWAS Consortium Bipolar Disorder Working Group 2011), major depressive disorder (Major Depressive Disorder Working Group of the Psychiatric GWAS Consortium et al. 2013), schizophrenia (Schizophrenia Working Group of the
