New research suggests that poor sleep affects mood in women with bipolar disorder.
Researchers at Penn State University found that poor sleep quality seems to exacerbate bipolar disorder, which is a brain condition that causes unusual shifts in mood, energy, activity levels and the ability to carry out day-to-day tasks.
"Patients with bipolar disorder often suffer with sleep problems even when many of their other symptoms are well-controlled," Dr. Erika Saunders, chair of department of psychiatry at Penn State College of Medicine, said in a statement. "Improving their sleep could not only better their quality of life, but also help them avoid mood episodes."
For the study, researchers collected and analyzed data from more than 200 people. They looked at the effect of sleep quality at the beginning of the study on mood outcome over the next two years. They measured mood outcome by the severity, frequency and variability of depressive or manic symptoms.
They found that poor sleep affected bipolar women more than it affected men with the brain disorder. In women, poor sleep quality predicted increased severity and frequency of depression and increased severity and variability of mania in women. Among men, baseline depression score and a personality trait called neuroticism were stronger predictors of mood outcome than sleep quality.
"There is some suggestion from animal models that reproductive hormones affect the circadian rhythm system, which is a biological system that affects our need to sleep," Saunders said. "It could be that reproductive hormones are biologically affecting sleep in women and therefore also affecting mood outcomes. Or, it could have more to do with the type of sleep that women are getting. We'll have to do more investigation into the biological underpinnings to understand that better."
Previous studies have shown that poor sleep quality is a symptom of depressive and manic episodes, and that lack of sleep can trigger mania.
The findings are detailed in the Journal of Affective Disorders.
