Sleep Disturbance and Depression Symptoms Mediate Relationship Between Pain and Cognitive Dysfunction in Lupus

OBJECTIVE: To determine whether sleep disturbance and symptoms of depression mediate the relationship between pain and cognitive dysfunction (CD) in a sample of 115 patients with systemic lupus erythematosus (SLE). METHODS: A total of 115 patients with SLE completed questionnaires regarding pain, perceived stress, depression, sleep, and CD. Relationships among pain, sleep, depression, and CD were assessed using bootstrap mediation models, controlling for race/ethnicity, fibromyalgia diagnosis, current corticosteroid use, disease activity and damage, and perceived stress. RESULTS: Mediation analyses indicated that the effect of pain on CD was mediated by sleep disturbance (β = 0.30) and depression symptoms (β = 0.33). These effects were maintained even after controlling for the aforementioned covariates, of which only disease activity (β = 0.20) and stress (β = 0.22) remained significantly linked to CD (overall model R2 = 0.53; all P < 0.05). CONCLUSION: After controlling for disease activity and perceived stress, the relationship between pain and CD was explained by sleep disturbance and depression symptoms. Although these relationships need validation in longitudinal studies with additional measurement modalities, our findings may indicate promising, nonpharmacologic intervention avenues for SLE patients with pain and CD. Specifically, cognitive behavioral therapies for depression and sleep are known to reduce distress and enhance functioning across various psychosocial domains. Given the symptom burden of SLE, interventions that maximize potential benefits without the use of additional pharmacologic treatments may be of particular utility.