Impact of Sleep Disorders on Depression and Health-Related Quality of Life in Multiple Sclerosis

Background: Patients with multiple sclerosis (MS) commonly experience sleep disturbance, and poor sleep in MS is independently associated with depression and poorer health-related quality of life (HRQoL). However, there is limited research examining the impact of clinical sleep disorders, above and beyond sleep problems, in MS. Of the sleep disorders, insomnia and sleep apnea are the most common and potentially concerning in patients with MS, yet to date there are no studies directly comparing how these two sleep disorders impact depression and HRQoL in patients with MS.

Objectives: The goal of this study is to examine the impact of clinical sleep disorders on the patient-reported outcomes of (1) HRQoL and (2) depressive symptoms in MS. This study expands upon previous studies which have shown that patients with MS and comorbid sleep problems (but not necessarily clinically diagnosed sleep disorders) are more likely to report reduced functioning, poorer HRQoL, and increased depression compared to patients without sleep problems.

Methods: Retrospective chart review of 180 adult patients (age >18) with MS and either insomnia or sleep apnea (central or obstructive) who sought treatment for either condition at a large hospital system in the Midwest U.S. between January 2008 and September 2015. Participants completed the Euro-QOL five dimensions questionnaire (EQ-5D) measure of HRQoL and the Patient Health Questionnaire (PHQ-9) measure of depressive symptoms through the patient-reported outcomes data collection project – The Knowledge Program. Analysis will include a chi-square test to determine if sleep disorder diagnosis (insomnia vs. sleep apnea) is associated with at least moderate depression (PHQ-9 ≥ 10). Independent samples t-tests will test if there is a significant difference in average PHQ-9 and EQ-5D scores for the two sleep disorder groups. The independent effect of sleep disorder diagnosis on PHQ-9 score and EQ-5D index will be assessed through separate multivariable linear regression models. We will also explore potential moderating and mediating variables of these relationships. 

Results: In progress.

Conclusions: A better understanding of how sleep disorders impact mood and HRQoL in MS has potential to inform assessment and intervention, as depression, insomnia and sleep apnea are widely regarded as treatable through interventions like cognitive behavioral therapy and positive airway pressure treatment.