What Domains of Quality of Life are Risk Factors for Depression in Patients with Epilepsy?

Depression affects quality of life (QOL) in patients with epilepsy, but this study investigated which domains of QOL represent risk factors for depression. Ninety-two patients were asked to complete the Quality of Life Inventory in Epilepsy-31-P (QOLIE-31-P) as a QOL questionnaire, the Side Effects and Life Satisfaction (SEALS) inventory to identify effects of antiepileptic drugs on cognition, and the Neurological Disorders Depression Inventory for Epilepsy (NDDI) for rapid screening of depression. Significant factors were entered into logistic backward elimination to investigate risk factors for depression. Major depression was seen in 18 of the 92 patients (19.6%). No significant differences were seen between depression and non-depression groups in seizure-related or demographic variables. However, NDDI score correlated with frequency of complex partial seizure. Energy/Fatigue and Emotional Well-Being subscales in QOLI-31-P and the Worry subscale in SEALS remained as QOL factors impacting on depression. Mean onset of depression was approximately 4 years before the time of the investigation. QOL subscales representing risk factors for depression were not seizures, but health-related QOL factors in QOLIE-31-P and SEALS. Confirmation of these scores may facilitate the management of depression and the achievement of better QOL in patients with epilepsy.