A connection between poor sleep quality and bipolar disorder (BD) has been obvious to scientists for decades. Periods of sleep disturbances often happen in conjunction with episodes of depression, mania or hypomania (an emotional state not quite as profound as true mania) in bipolar disorder patients. Some studies have strongly suggested that sleep disruptions might even trigger manic and hypomanic episodes.
What hasn’t been as clear is the true nature of the relationship between sleep and bipolar disorder. Does poor sleep cause manic episodes, or is it the reverse? Or are sleep disturbances an unfortunate side effect of medications used to treat bipolar disorder?
Some or all of these possibilities could be true, but some scientists have also wondered whether patterns of poor sleep might actually make it more likely that an otherwise healthy person could develop bipolar disorder. A new study provides compelling evidence of just such a connection.
Is Poor Sleep a Bipolar Trigger?
Many studies have examined the association between sleep and bipolar disorder. Bipolar disorder patients have shown a tendency to have poor sleep patterns, even when they’re not in a manic or depressed state. Other studies have shown that sleep disruptions can cause manic episodes and that improvement of sleep patterns between episodes can reduce the risk of relapse.
But some researchers have theorized that if sleep and bipolar disorder are so closely interconnected, it may be possible that patterns of poor sleep could put a healthy person at an increased risk of developing bipolar disorder. Some studies have pursued that idea, but until now, they’ve been small and have been complicated by the inclusion of people who have a genetic predisposition for bipolar disorder.
A new study recently published in the journal Translational Psychiatry attempts to focus on a large sample of healthy subjects (those who do not have a family history of bipolar disorder) to see whether or not there is a connection between sleep and bipolar disorder risk.
In the study, participants were assessed using the hypomanic personality scale (HPS), a questionnaire that has proven effective at predicting vulnerability to bipolar disorder. Their sleep patterns were also assessed using either sleep-measuring devices or a sleep-quality questionnaire. Finally, the study excluded subjects who had illnesses or were taking medications that might affect their sleep quality.
Ultimately, the study found a significant correlation between sleep and bipolar disorder risk. Those participants who showed characteristics that predict a high risk for bipolar disorder were more likely to also have sleep problems, including poor sleep quality, day-to-day sleep variability, low sleep duration, and daytime sleepiness. In particular, those who had a high level of variability in the quality of their sleep from day to day seemed to be at the highest risk for developing bipolar disorder.
Preventing Bipolar Disorder by Sleeping
Although these findings don’t, by any means, present a complete understanding of the relationship between bipolar disorder and sleep, they do suggest some encouraging possibilities. If poor sleep quality does, indeed, predispose someone to be vulnerable to developing bipolar disorder, addressing sleep disruptions could be a relatively easy way to head off the disorder before it strikes.
Sleep problems are typically easy to spot and treat, and they don’t usually carry the social stigma that sometimes prevents people from seeking treatment for mental illness. For individuals who are at high risk of developing bipolar disorder, an effective, life-changing preventive measure may be as simple as getting a good night’s sleep.