Effect of continuous positive airway pressure on symptoms of anxiety and depression in patients with obstructive sleep apnea

Purpose The objective was to assess the effect of continuous positive airway pressure (CPAP) on symptoms of anxiety and depression in patients with obstructive sleep apnea (OSA). We hypothesized a decrease in symptoms at follow-up, but that improvement relied on CPAP adherence. Methods The sample comprised 468 patients (mean age 55.5 years (SD = 12.0), 72% men) with OSA who received CPAP at a Norwegian hospital. OSA was diagnosed according to standard respiratory polygraphy. Mean baseline respiratory event index (REI) was 28.4 (SD = 20.6). Symptoms of anxiety and depression were assessed prior to CPAP treatment and at follow-up after a median of 20 weeks, range 6–52 weeks, with the Hospital Anxiety and Depression Scale (HADS). Patients were classified as CPAP adherent (≥ 4 h per night) or non-adherent (< 4 h per night). Results There was a significant decrease in anxiety scores from baseline (mean = 5.16, SD = 3.94) to follow-up (mean = 4.76, SD = 3.81), p < 0.001. Similarly, depression scores decreased from baseline (mean = 4.31, SD = 3.66) to follow-up (mean = 3.89, SD = 3.69), p < 0.001. Cohen’s d (0.19 and 0.18, respectively) indicated small effect sizes. The reduction in anxiety scores did not depend on CPAP adherence (no interaction effect F (1, 466) = 0.422, p = 0.516), whereas the reduction in depression scores were seen only in the CPAP adherent group (interaction effect F (1, 466) = 7.738, p = 0.006). Conclusions We found a decrease in symptoms of anxiety and depression from baseline to follow-up of CPAP treatment. The improvement in symptoms of depression was depending on CPAP adherence. This underlines the importance of adherence for optimal effect of CPAP treatment.