HCRT and narcolepsy-cataplexy syndrome: Narcolepsy Type 1 (NT1) is a sleep‐related neurological disorder characterized by abrupt changes in arousal, including sleep attacks, cataplexy, and fragmented nighttime sleep, which arises because of decreased signaling by the receptors of sleep‐regulating hormone orexin (a.k.a. hypocretin) in the hypothalamus.