Western Australia – A group of researchers from the University of Australia and Hospital of Perth have discovered that the development of sleep apnea and depression may be related and that treatment with continuous positive airways pressure (CPAP) is helpful to both conditions. The findings of the study were published in the journal of Clinical Sleep Medicine.

According to the American Academy of Sleep Medicine (AASM) more than 25 million adults in the US have sleep apnea, a condition whereby breathing stops briefly and repeatedly during sleep. Chronic snoring is the most common sign of sleep apnea.

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.

Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts. You may have sleep apnea if you snore loudly, and you feel tired even after a full night’s sleep. Credit: Mayo Clinic

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

“Effective treatment of obstructive sleep apnea resulted in substantial improvement in depressive symptoms, including suicidal ideation […] The findings highlight the potential for sleep apnea, a notoriously underdiagnosed condition, to be misdiagnosed as depression.” 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 in a statement to the AASM.

The study

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 median 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.


Hillman has concluded in the study, based on his new research, that sleep apnea is often misdiagnosed for depression because patients have similar symptoms in both affections. Yet, patients with sleep apnea feel depressed because they don’t get enough sleep at night, whereas for the rest of the patients depression can have various causes.

In Hillman’s opinion, depression and sleep apnea have to be correctly diagnosed in order to have progress. He believes people’s suicidal intentions could be cured by simply treating their sleeping disorders.

Source: Journal of Clinical Sleep Medicine