Correlates of depressive symptoms in patients with obstructive sleep apnea

Depressive symptoms are common in many different medical illnesses, including obstructive sleep apnea. Previous studies have shown conflicting results on the relationship of depressive disorders and depressive symptoms with sex and severity of sleep apnea.

Ninety-two men and 29 women diagnosed with moderate to severe OSA were reviewed for the presence of depressive symptoms and degree of sleepiness using the Beck Depression Inventory (BDI) scores and Epworth Sleepiness Scale scores at the time of polysomnography.

Higher levels of depressive symptoms were reported by women (15.4 +/- 10.5) than men (8.1 +/- 6.6) (p < .01). At least mild depressive symptoms (BDI > 10) were found in 44.6% of all patients, including 62% of women and 39% of men (p < .05). At least moderate depression was present in 11.6% of patients (BDI >19), including 28% of women and 6% of men (p < .01). The BDI was positively related (p < .001) to the desaturation nadir. The degree of daytime sleepiness was unrelated to depression severity.

Depressive symptoms are more common and more severe in women with OSA than in men, and this is consistent with results of previous studies that showed that depression is more common in women in a broad range of settings. Surprisingly, in this study, milder oxygen desaturation nadirs were associated with worse depression scores, especially in women, suggesting that depressive symptoms in female patients with obstructive sleep apnea originate from factors other than traditional measures of obstructive sleep apnea severity.