Editing Advanced sleep phase disorder (section)

==Symptoms==
Individuals with ASPD report being unable to stay awake until conventional bedtime, falling asleep too quickly and/or early in the evening, and being unable to stay asleep until their desired waking time, experiencing early morning [[insomnia]]. When someone has advanced sleep phase disorder their [[melatonin]] levels and core body temperature cycle hours earlier than an average person.<ref>{{Cite web | url=http://www.sleepdex.org/fasps.htm | title=Advanced Sleep-Wake Phase Disorder - Symptoms, Diagnosis, Treatment}}</ref> These symptoms must be present and stable for a substantial period of time to be correctly diagnosed.{{citation needed|date=December 2020}}