Effect of CPAP treatment on residual depressive symptoms in patients with major depression and coexisting sleep apnea: Contribution of daytime sleepiness to residual depressive symptoms

BackgroundAlthough extensive studies have indicated a relationship between obstructive sleep apnea (OSA) and depressive symptoms, the effect of continuous positive airway pressure (CPAP) treatment on residual depressive symptoms in patients with both major depressive disorder (MDD) and coexisting OSA has not been examined.MethodsSeventeen patients with continued MDD despite pharmacotherapy such as antidepressants and/or benzodiazepines, who also had comorbid OSA, were required to complete the Beck Depression Inventory (BDI), Hamilton Rating Scale for Depression (HRSD), and Epworth sleepiness scale (ESS) at the commencement of the study and then again after 2 months of CPAP treatment.ResultsBDI and HRSD scores decreased from 19.7 to 10.8 and 16.7 to 8.0 after 2 months of CPAP treatment (both p < 0.01). We also found significant correlations among the improvement rates in BDI, HRSD and ESS scores (R = 0.86 and 0.75, both p < 0.01). The mixed effect model demonstrated a significant ESS effect on BDI and HRSD.ConclusionsThe results suggest that MDD patients with residual depressive symptoms despite pharmacotherapy who also have symptoms of suspected OSA, such as loud snoring, obesity, and daytime sleepiness, should be evaluated for sleep apnea by polysomnography and treated with an appropriate treatment such as CPAP. CPAP treatment may result in a significant improvement of residual depressive symptoms due to the improvement of daytime sleepiness in these patients.