The APOE ε4 allele is the strongest known genetic risk factor for late-onset AD.9 Past research explored the convergence of neuropsychiatric symptoms in MCI, such as apathy, depression, and agitation, and APOE ε4 allele status; additive interactions between symptoms, including depression and apathy, and a positive APOE ε4 status were found to be associated with increased risk for developing dementia.10 However, the impact of apathy-APOE ε4 interactions, in isolation of other neuropsychiatric symptoms, on conversion from MCI to Alzheimer’s disease dementia (ADD) has not been examined. The gene discussed is APOE; the disease is major depressive disorder.