Determining the Role of Sex and APOE4 status on Psychosis in Alzheimer's Disease.

BackgroundPsychosis occurs in approximately 41% of patients living with Alzheimer's disease. Previous findings from our group based on analyses of a neuropathological cohort suggest that among AD patients with Lewy Body pathology, female APOE4 homozygotes are at significantly greater risk of psychosis. This study aims to replicate this finding in a clinical cohort using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset.MethodsOur group used data from a sample of patients with AD in the ADNI database from the ADNI1, ADNI2, ADNI3, and ADNIGO studies. We defined psychosis status as experiencing hallucinations or delusions at one time point based on the Neuropsychiatric Inventory. We then used forward binary logistic regression to determine if sex and APOE4 status are predictors of AD + P.ResultsIn total there were 204 participants who met the inclusion criteria, 133 of which were male, and 71 of which were female. Fifty-six patients were APOE4 non-carriers, 109 patients were APOE4 heterozygote carriers, and 39 were APOE4 homozygote carriers. In total, there were 59 patients with psychosis. When adjusting for mini mental state examination score, adjusted hippocampal volume, and age, we demonstrate that female APOE4 homozygotes have a significantly increased risk of psychosis compared to other groups (P = 0.0264, OR = 19.50).DiscussionThe results of our study demonstrate a significant association between psychosis risk and female APOE4 homozygotes, thus corroborating findings from a neuropathological cohort. The effects of APOE ε4 on psychosis risk are significant only in females, and not in males.