Sleep and Bipolar Disorder
Bipolar disorder is a lifelong mental health condition. It causes extreme changes in mood. There are episodes of emotional highs, called mania, and emotional lows, called depression. Bipolar disorder can affect your energy level. It can also affect your ability to do daily tasks.1
Doctors do not know the cause. They also cannot prevent it. Bipolar disorder may be linked to disturbed sleep. Changes in the body's sleep-wake cycles may connect sleep to bipolar disorder. Changes in brain cells may also be involved.2
Sleep disorders are common
Up to 50 percent of the world's population has disturbed sleep. Disturbed sleep affects sleep quality, quantity, and duration. Common types of disturbed sleep are:3
- Insomnia
- Obstructive sleep apnea
- Restless legs syndrome
- Narcolepsy
Disturbed sleep is even more common in people with mental health conditions. Good sleep regulates biological processes like behavior and mood.2
Sleep and bipolar disorder
Disturbed sleep is a hallmark of bipolar disorder. Doctors use sleep to figure out when an episode may start. This is because disturbed sleep worsens before an episode. The disruption peaks during the episode.2,4,5
How is sleep affected during an episode?
During mania, 66 to 99 percent of people sleep less. It also takes longer to go to sleep. Plus, a lack of sleep can cause mania. During bipolar depression, 40 to 100 percent of people have insomnia. Up to 78 percent of people sleep too much.2
Sleep is impacted even outside of mania and depression. The time between episodes, called the interepisode period, is disturbed. Up to 70 percent of people have insomnia during the interepisode period. Twenty-five percent sleep too much.2,5
Compared to those without bipolar disorder, sleep in the interepisode period is different in these ways:4
- Lower quality
- Longer sleep time
- It takes longer to fall asleep
- It takes longer to wake up
What is the connection?
Experts have found several connections between sleep disturbances and mental health conditions.
Circadian rhythm
The circadian rhythm may link sleep to mental health conditions. The circadian rhythm is the body's internal clock. It works in 24-hour cycles. It uses exposure to light and dark to create a sleep-wake cycle.2
This cycle impacts everything we do. The circadian rhythm is controlled by a part of the brain called the suprachiasmatic nucleus. Good sleep is key in keeping a healthy circadian rhythm.6
Disturbed circadian rhythms may impact bipolar disorder. When the body cannot synchronize cues from the environment with its internal clock, it may raise the risk for mental health issues. Experts have seen upset circadian rhythms in people with bipolar disorder.2,7
Neuroglial cells
Neuroglial cells are cells of the central nervous system. These cells include:2
- Astrocytes
- Microglia
- Oligodendrocytes and the cells they come from
These cells keep the brain healthy. Changes to these cells occur in people with bipolar disorder. There are fewer astrocytes in people with bipolar disorder, and they do not work as well. Astrocytes help regulate sleep, so these changes may link disturbed sleep and bipolar disorder.2
Common drugs used to treat bipolar disorder are lithium and valproic acid. These drugs affect astrocytes. This makes a strong case for neuroglial cells' involvement in bipolar disorder.2
Impact of sleep on bipolar disorder
Bipolar disorder is life-threatening. Up to half of those diagnosed attempt suicide. Up to 20 percent complete suicide.2,5
Having the disease is hard enough. Disturbed sleep, especially when chronic, worsens episodes. This affects quality of life. It also makes it harder to find working treatments.2,5
Treatment of bipolar disease
Since sleep is linked to bipolar disorder, experts think it should be treated like a symptom of the disease. A 2022 study said that doctors should correct disturbed sleep during all phases of the disease. This may lead to fewer or less severe episodes.4