Bipolar disorder may affect sleep in many ways. For example, it can lead to:
Insomnia, the inability to fall asleep or remain asleep long enough to feel rested (resulting in feeling tired the next day). Hypersomnia, or over-sleeping, which is sometimes even more common than insomnia during periods of depression in bipolar disorder. Decreased need for sleep, in which (unlike insomnia) someone can get by with little or no sleep and not feel tired as a result the next day.
Delayed sleep phase syndrome, a circadian-rhythm sleep disorder resulting in insomnia and daytime sleepiness.
REM (rapid eye movement) sleep abnormalities, which may make dreams very vivid or bizarre.
Irregular sleep-wake schedules, which sometimes result from a lifestyle that involves excessive activity at night.
Co-occurring drug addictions, which may disrupt sleep and intensify pre-existing symptoms of bipolar disorder.
Co-occurring sleep apnea, which may affect up to a third of people with bipolar disorder, which can cause excessive daytime sleepiness and fatigue.