MAPT and early-onset autosomal dominant Alzheimer disease: Whereas the importance of sleep for survival and cognitive performance has been recognized and studied for over a century,1,2 only during the last decade has research begun to mechanistically unveil the bidirectional relationship between sleep and long-term health of the CNS.3 The most common form of dementia, Alzheimer disease (AD), is hallmarked by the pathologic accumulation of both extracellular β-amyloid (Aβ) and intracellular tau proteins in amyloid plaques and neurofibrillary tangles, respectively.