Rational heterodoxy: Cholesterol reformation of the amyloid doctrine

► Cholesterol dysregulation initiates pathology in late-onset Alzheimer's disease. ► The amyloid precursor protein regulates cholesterol homeostasis in the brain. ► Amyloid accumulation is not necessary to initiate late-onset Alzheimer's disease. ► Cholesterol dysregulation may be a key initiator of multiple mental disorders.