Determinants of quality of life in epilepsy.

Although depression is associated with diminished quality of life (QOL) in epilepsy patients, the relative contributions of epilepsy-specific concerns, as well as clinical and cognitive variables of QOL, have not been simultaneously investigated. A comprehensive neuropsychological test battery including the Beck Depression Inventory (BDI), Epilepsy Foundation of America's (EFA) Concerns Index, MMPI-2, QOLIE-89, WAIS-III, and Selective Reminding was administered to 115 epilepsy surgery candidates with normal Full Scale IQs. Linear regression analyses were performed to identify significant predictor combinations of QOLIE-89 total score. Regression analysis demonstrated that depressive symptomatology, whether reflected by the BDI (R2=0.45) or Depression scale of the MMPI-2 (R2=0.36), was a robust individual QOL predictor. Seizure Worry from the EFA Concerns Index was nearly as effective as the BDI in predicting QOLIE-89 (R2=0.42). When the BDI and EFA Concerns Index were combined into the same regression, both factors continued to contribute significantly to the QOLIE-89 total score, with both variables accounting for 61% of the variance. Although patients who developed their seizures at an older age had poorer QOL and patients with higher educational levels reported higher QOL, neither factor was related to QOL after accounting for the effects of psychological variables and epilepsy-related concerns. Although quality of life has multiple determinants, symptoms of depression and seizure worry are the most important factors affecting QOL in patients with intractable epilepsy.