To date, it is difficult to interpret the data regarding sex differences in the genetic architecture of psychiatric disorders, due to differences across studies in ascertainment and methods, which have yielded noncomparable samples in terms of severity, comorbidity and complications of mental disorders. The samples in current GWAS studies have not generally been systematically selected. Even though the large numbers may reduce the impact of some sampling biases, future studies should examine the effects of ascertainment, to examine whether findings may differ by the sex and severity of the disorder in the proband.
