Erika Thiel, PA-S
Obstructive Sleep Apnea and Depression
Obstructive sleep apnea (OSA) is a disease characterized by recurrent interruptions in airflow that occur while sleeping. These episodes of apnea cause sleep disturbances and oxygen desaturation. OSA and depression present similarly to one another. Both diseases share the symptoms of disturbed sleep, restlessness, anxiety, weight gain, tiredness, traffic accidents, and impaired psychosocial health. The similarities between them makes differentiating between the two diseases difficult and can lead to the under-diagnosis of OSA and the misuse of antidepressant therapy.1 When left untreated, OSA can cause CVD, hypertension, stroke, and excessive daytime sleepiness.2 It is important to rule out OSA in patients presenting with the symptoms of depression to eliminate the risks associated with the improper management of OSA.
Studies have shown that up to 63% of patients with OSA experience the symptoms of depression.3 In animal models, episodes of nightly, recurrent hypoxemia have been associated with cell loss in areas rich in noradrenergic and dopaminergic pathways, which influence the regulation of mood, sleep, and wakefulness.4 The mainstay of treatment for OSA is continuous positive airway pressure (CPAP). Depression severity has been shown to decrease in patients with OSA after the implementation of CPAP therapy.5 Habukawa et al. studied patients with depression who were unresponsive to antidepressants for greater than 6 months, and they found that 2 months of CPAP therapy decreased depression rating scores. CPAP therapy decreased the Hamilton Rating Scale for Depression scores from 16.7 to 8.0 and the Beck Depression Inventory scores from 19.7 to 10.8.6 Similarly, Edwards et al. found that three months of CPAP therapy led to a 70.7% decrease in the percentage of participants in their study with depression.5 When treated correctly, the symptoms of depression that present in patients with OSA can be decreased. Not surprisingly though, OSA sometimes goes undiagnosed. McCall et al. studied suicidal MDD outpatients with insomnia and found that 14% of the participants in their study had unsuspected OSA.7
Because OSA and depression present similarly to one another, providers should be cautious when distinguishing between the two conditions. While some patients with OSA exhibit the classic features of OSA, such as obesity and a large neck circumference, not all patients with OSA present in this manner. When depression appears to be unresponsive to antidepressant therapy, providers should consider the possibility of undiagnosed OSA. Furthermore, if a patient is diagnosed with OSA, it is then important to determine whether the patient’s depressive symptoms are a result of their OSA, or whether the patient has a comorbid depression disorder. A comorbid depression disorder may cause decreased CPAP adherence and require antidepressant treatment. Seeing as depression and OSA treatments differ, it is important to establish the correct diagnosis or diagnoses early on to ensure that the patient’s condition is properly managed.