http://goo.gl/PQb5IZ
Sleep and circadian rhythms are also known to play a part in bipolar disorder. Manic phases generally see the individual sleeping less; conversely, during depressive periods, sleep is often more prevalent.
Some researchers have concluded that sleep might be a factor in bipolar relapses, or perhaps an early warning sign of bipolar events on the horizon.
Below is a list of the specific sleep and circadian phenotypes that were found to significantly vary between those with bipolar disorder and those without:
- Mean awake duration: average length of time spent awake per day
- Amplitude: a measure of the strength of an individual's circadian rhythm
- Hill acrophase: time of day at which activity peaked
- Interdaily stability: the degree of variation in levels of activity each day
- Interdaily variability: a measure of the fragmentation of circadian rhythm
- Median activity: average amount of activity per day
- Relative amplitude: the difference between the least and the most intense periods of activity across 24 hours
- Mean length of sleep bouts during the sleep period: average amount of time spent in each bout of sleep during the night
- Mean number of sleep bouts during awake period: average length of naps during the day
- Time of sleep offset: time of awakening in the morning
- Mean total minutes scored awake: average time spent awake per day
- WASO: total minutes spent awake after the onset of sleep.