CPAP therapy lowers depressive symptoms in people with obstructive sleep apnea

A new study shows that depressive symptoms are extremely common in people who have obstructive sleep apnea, and these symptoms improve significantly when sleep apnea is treated with continuous positive airway pressure therapy.

Results show that nearly 73 percent of sleep apnea patients (213 of 293 patients) had clinically significant depressive symptoms at baseline, with a similar symptom prevalence between men and women. These symptoms increased progressively and independently with sleep apnea severity.

However, clinically significant depressive symptoms remained in only 4 percent of the sleep apnea patients who adhered to CPAP therapy for 3 months (9 of 228 patients). Of the 41 treatment adherent patients who reported baseline feelings of self-harm or that they would be "better dead," none reported persisting suicidal thoughts at the 3-month follow-up.

"Effective treatment of obstructive sleep apnea resulted in substantial improvement in depressive symptoms, including suicidal ideation," said senior author David R. Hillman, MD, clinical professor at the University of Western Australia and sleep physician at the Sir Charles Gairdner Hospital in Perth. "The findings highlight the potential for sleep apnea, a notoriously underdiagnosed condition, to be misdiagnosed as depression."

Study results are published in the September issue of the Journal of Clinical Sleep Medicine.

The American Academy of Sleep Medicine reports that obstructive sleep apnea (OSA) is a common sleep disease afflicting at least 25 million adults in the U.S. Untreated sleep apnea increases the risk of other chronic health problems including heart disease, high blood pressure, Type 2 diabetes, stroke and depression.

The study group comprised 426 new patients referred to a hospital sleep center for evaluation of suspected sleep apnea, including 243 males and 183 females. Participants had a mean age of 52 years. Depressive symptoms were assessed using the validated Patient Health Questionnaire (PHQ-9), and the presence of obstructive sleep apnea was determined objectively using overnight, in-lab polysomnography. Of the 293 patients who were diagnosed with sleep apnea and prescribed CPAP therapy, 228 were treatment adherent, which was defined as using CPAP therapy for an average of 5 hours or more per night for 3 months.

According to the authors, the results emphasize the importance of screening people with depressive symptoms for obstructive sleep apnea. These patients should be asked about common sleep apnea symptoms including habitual snoring, witnessed breathing pauses, disrupted sleep, and excessive daytime sleepiness.