The largest genetic map of mental health disorders to date reveals there are three groups of highly genetically related disorders among eight psychiatric disorders. A gene related to nervous system development is a risk factor for all eight disorders studied. The RBFOX1 gene is implicated in seven of the eight disorders. ADHD and depression share 44% of genetic risk factors common in the general population. 109 pleiotropic loci affect more than one disorder. These pleiotropic loci are within genes that show heightened expression in the brain through the lifespan, beginning during the second trimester of pregnancy.