Apolipoprotein E epsilon4 allele increases risk for psychotic symptoms in Alzheimer's disease.

The apolipoprotein E (ApoE) epsilon4 allele is a well-documented genetic risk factor for sporadic Alzheimer's disease (AD). Its association with psychopathology among AD patients has been the subject of discrepant reports. We aimed to determine whether ApoE epsilon4+ and epsilon4- AD patients exhibit a different risk profile for psychotic symptoms and other behavioral disturbances.