APP and Alzheimer disease: In this study, for confirmation of effects of brexpiprazole on BPSD‐like symptoms in animal models of Alzheimer's dementia, we evaluated the effects of brexpiprazole on aggressive behavior caused by resident–intruder test in Tg2576 mice and on increased nocturnal activity in APPSL‐Tg mice overexpressing a mutant form of APP with the Swedish and London mutations.