HCRT and Alzheimer disease: msAD showed earlier bed- times compared with those with mAD (p = 0.04). Positive correlation in the global AD group between CSF orexin and t-tau levels (r = 0.32; p = 0.03). A positive correlation was evident between CSF orexin and t-tau (r = 0.64; p< 0.001) and p-tau (r = 0.56; p = 0.002) protein levels in AD association between CSF orexin levels and sleep onset latency (β = 0.091; p = 0.03) in AD