Tags: Disease.
Advanced sleep phase disorder (ASPD) also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder or advanced sleep phase syndrome (ASPS) is a condition in which patients feel very sleepy and go to bed early in the evening (e.g. 6:00โ8:00 p.m.) and wake up very early in the morning (e.g. around 3:00 a.m.).