Abstract
OBJECTIVES: The association between insomnia and quality of life (QOL) in epilepsy is poorly understood and may involve interactive variables. We aimed to investigate whether and how insomnia, levels of depression and anxiety symptoms interact to influence QOL in people with epilepsy (PWE). METHODS: A consecutive cohort of 179 PWE was enrolled. We collected data on insomnia, levels of depression and anxiety symptoms, and QOL. The Insomnia Severity Index (ISI), Depression Inventory for Epilepsy (NDDI-E), Generalized Anxiety Disorder-7 (GAD-7), and QOL in Epilepsy Inventory (QOLIE-31) were used. The direct, indirect, and total effects of insomnia on QOL were estimated based on a moderated mediation model. RESULTS: Depression symptom levels mediated the association between insomnia and QOL (B = 0.09 SE = 0.03, p = 0.01). Depression symptom levels accounted for 34.7% of the total effect of insomnia on QOL. The mediating effect of depression symptom levels was positively moderated by anxiety symptom levels (B = 0.09, SE = 0.03, p = 0.01). CONCLUSION: The effect of insomnia on QOL can be partially explained by the mediation of depression symptom levels. Additionally, improving anxiety symptoms may attenuate the indirect effect of insomnia on QOL through depression symptom levels.