Comorbid depression in obstructive sleep apnea: an under-recognized association

Background: Obstructive sleep apnea (OSA) and depression may coexist in the same patient. This article aims to review the link between OSA and comorbid depression and critically evaluate the results of studies that assessed the correlation between OSA and depression, the impact of OSA treatment on comorbid depression, and the impact of comorbid depression on continuous positive airway pressure (CPAP) adherence. Methods: An integrative review was conducted on English language studies and reports that assessed the relationship between OSA and depression. Studies were identified by searching PubMed, Web of Science and Google Scholar databases, and reference lists of included studies. Results: Generally, cross-sectional studies show a higher prevalence of depression among OSA patients with both community and sleep disorder clinic samples. Nevertheless, the relationship between OSA and depression is complicated by the fact that the disorders have overlapping symptoms. Longitudinal studies demonstrate an increased risk of developing depression among people with OSA, as well as an association between OSA severity and the likelihood of developing depression. On the other hand, studies assessing the impact of CPAP therapy on depression among OSA patients report conflicting results. Therefore, it is essential to consider how the disorders affect one another and to understand the clinical consequences of treating each disorder in isolation. Conclusion: Depression is prevalent among patients with OSA both in the community and in sleep disorder clinics. Clinicians in general should be aware of this significant association and should aim to treat both disorders.