The end stage of Alzheimer's disease is complex and many-faceted - which is all the more reason to focus on prevention and early repair of the root causes rather than the present strategy of patching the cracks in the dam late in the process: "A protein long suspected as the culprit behind the brain disorder might actually release not just one, but two components that can cause nerve cells to self-destruct. In theory, the breakdown of the protein, called APP for short, could unleash a double whammy of harmful effects on nerve cells. Much of the drug research in the field now focuses on the first component of APP discovered to have a strong link to Alzheimer's disease. That component, the amyloid beta peptide, collects in abnormal plaques in the brain that are a diagnostic sign of the ailment. But a second molecule split off from APP, the N fragment or N-APP, was found to trigger a chain of events that also destroys neurons. ... The question is, how much of the neurodegeneration is triggered by the amyloid beta peptide and how much by N-APP?"