Current belief is both. The reason you get Alzheimer's at a later stage in life is because as we age sleep degrades, a big part of this degradation is that we

Current belief is both. The reason you get Alzheimer's at a later stage in life is because as we age sleep degrades, a big part of this degradation is that we get less slow wave oscillations as we age. Less SWOs, means more build up of amyloids. Years of lack of sleep also leads to build up of amyloids. Of course this is only meaningful if the amyloid Alzheimer's connection is solved.