In this first report from the PGC Cross-Disorder Group, we analyse data on genome-wide single-nucleotide polymorphism (SNP) for the five PGC disorders to answer two questions. First, what information emerges when all five disorders are examined in one GWAS? When risk is correlated across disorders, pooled analyses will be better powered than individual-disorder analyses to detect risk loci. Second, what are the cross-disorder effects of variants already identified as being associated with a specific psychiatric disorder in previous PGC analyses? We aimed to examine the genetic relation between the five psychiatric disorders with the expectation that findings will ultimately inform psychiatric nosology, identify potential neurobiological mechanisms predisposing to specific clinical presentations, and generate new models for prevention and treatment.
