Most recently, the prospective APOE*ε4 4-year risk for increased depressive symptomology and incident depression status was reported in a Swedish study of 800 older adults who were depression-free at baseline and who remained free of significant cognitive decline over the study period.17 However, this contrasts with other longitudinal studies that identify no association between APOE*ε4 and depression.25 There remains a need to replicate these findings and to extend the examination of risk associated with APOE*ε4 over a longer follow-up, and to examine this risk across the lifespan. This evidence concerns the gene APOE and Mental deterioration.