The high prevalence of obstructive sleep apnea among patients with bipolar disorders

Sleep plays an important role in maintaining stability in bipolar disorders, and sleep disturbances can trigger mood episodes. Obstructive sleep apnea (OSA) is a common sleep disorder, yet the co-occurrence with bipolar disorder has not been methodically studied.

This is a chart review of 482 consecutively seen patients with a bipolar disorder who underwent routine screening for OSA using a self-report sleep apnea questionnaire. Positive screens were referred for a sleep study.

A positive screen was found in 214 (44.4%) patients. Sleep studies were obtained on 114 patients, and 101, were diagnosed with OSA: point prevalence 21%.

The 21% prevalence fails to consider the false negative rate of the questionnaire, or the exclusion of patients who screened positive but failed to get a sleep study. Taking these into consideration it is estimated that the true prevalence of OSA in this study may be as high as 47.5%. The co-occurrence of OSA and bipolar disorders is markedly higher than previously thought. Of note, OSA may play a role in refractory bipolar, disorders, and carries significant mortality and morbidity that overlap, with the mortality and morbidity found with bipolar disorders.

This was a retrospective study based on a self-report questionnaire. Polysomnographic confirmation was performed in only a subgroup of subjects.

The data suggest that unrecognized OSA may play a major role in the mortality and morbidity of bipolar disorders. All patients diagnosed with a bipolar disorder should be screened with an OSA questionnaire.