In general, very little is known about sleep considering that it is a state of consciousness in which we spend nearly a third of our lives. It is not clear why we sleep, although it is clear that we cannot function well without it.
Normal sleep patterns are a result of daily cycles in the brain that interact with our environment. In the absence of external cues, these daily cycles can become abnormal. For example, most people’s sleep schedule seems to be based on a 25-, not a 24-hour cycle. This isn’t a problem if we wake up at the same time every day, for example with an alarm clock, and we get other external cues that it is time to wake up (such as family members waking up and preparing breakfast, the sun rising, etc). These external cues reset our cycles every day, keeping us in step with a 24-hour day. However, if these daily cycles are impaired for long periods of time, serious problems may result.
Disturbed sleep is a common symptom of mania, typically in the form of decreased need for sleep. In extreme cases, people experiencing manic episodes can go for days without sleep, engaged in activities around the clock. These episodes of continuous activity can lead to death from cardiac causes if untreated.
We are gaining a better awareness that management of the sleep disturbances associated with bipolar disorder is associated with better outcomes. It may be that impaired sleep cycling is one of the core causes of bipolar disorder. It should also be kept in mind that what we call “bipolar disorder” could be the result of multiple different problems in brain functioning that can all lead to the same symptoms, perhaps explaining why some treatments work well for some people but not others, or why symptoms can vary so dramatically from one person to another.
Changes in medications can also cause sleep disturbances. The most common scenario occurs when a medication used for sleep, or that causes sleepiness is decreased or discontinued. In this situation, it is very common to experience “rebound insomnia” for several days.
Despite our ignorance in this area, it is important for everyone, especially those with bipolar disorder, to maintain a healthy sleep schedule. Changes in sleep should be reported to your doctor. Further information about sleep can be found in this National Institute of Health download.