In summary, our study highlights the importance of utilizing a variety of phenotypes, including individual dependence criteria in locus discovery for AD. The heterogeneity that underlies the diagnosis of AD due to the various combinations of individual criteria that can be endorsed to meet diagnostic criteria, is also true for major depression disorder (MDD), and has been shown to hinder GWAS 91. While significant increases in sample size can potentially overcome this heterogeneity (as has been shown in the GWAS of MDD 92), the study of individual criteria, alongside diagnosis and severity, can provide a more detailed characterization of common and specific genetic influences on aspects of AD, especially when viewing individual criteria as psychometric indices of various cut-points of AD liability, and may eventually shape individualized treatment based on criterion profiles and other related features, over and above a mere diagnosis of AD.
