Following on from the hypothesis of a role for the ApoE [varepsilon]4 and [varepsilon]2 alleles as risk and protective factors, respectively, for late-onset Alzheimer's disease (AD) came inevitable questions regarding other psychiatric conditions of late onset including depressive illness and schizophrenia. Is ApoE [varepsilon]4 a risk factor in these diseases and do carriers have an earlier age of onset? Does ApoE [varepsilon]2 have a protective role, with carriers of this allele having a later age of onset?
