phenotypes observed in our study. In addition, while previous studies on genetic architecture of comorbid psychiatric disorders are based on general population samples (Kendler et al. 2003; Kendler et al. 2011a; Krueger et al. 2002), our sample was ascertained based on AD diagnosis and ancestry information (Edenberg et al. 2010). The next step to confirm the similarity of genetic architecture between different populations would be to replicate the results in independent epidemiological samples.
