Educational reference
About this symptom
This is not insomnia. A person with insomnia wants to sleep and cannot; a person with reduced need for sleep sleeps considerably less than usual and does not feel tired.
People describe sleeping three or four hours and waking refreshed, or feeling that sleep is an unnecessary interruption. Because it does not feel like a problem, it is often not reported, and may be recalled only when a clinician asks specifically.
It is one of the more reliable indicators of mania and hypomania, and among the earliest changes many people notice before an episode develops. For that reason it features prominently in relapse planning: a sustained drop in sleep need, without tiredness, is often treated as an early warning sign worth acting on.
Distinguishing it from insomnia matters clinically, because the two point in different directions and are managed differently.