Altered quality of life in epilepsy: significance of interictal depression

Abstract

Background: Depressive disorders in people with epilepsy are a frequently encountered psychiatric comorbidity with prevalence rates of 10-60% of the patients depending on the type of the selected patient populations or differences in methodology for detecting psychiatric symptomatology. As a part of the burden of living with epilepsy they represent an important issue in the management of people with epilepsy being associated with poor quality of life and poor prognosis. Aim and method: We assessed the frequency and the impact of comorbid depressive disorder on the quality of life of people with epilepsy. The research was conducted on 106 patients with idiopathic epilepsy (41 males and 65 females), aged 18 to 60 years. All subjects underwent the same research protocol applied interictally. Comorbid depressive disorder was diagnosed according to ICD-10 diagnostic criteria for affective and delusional disorders and diagnosis was supported by evaluation on Hamilton Depression Rating Scale (HAM-D-17). Health-related quality of life was measured by Quality of Life in Epilepsy Inventory-31 (QOLIE-31). Statistical analysis included analysis of variance, correlation analysis, T-test analysis. Results: Comorbid depressive disorder affected 30(28.3%) of all evaluated epilepsy patients. Based on HAM-D-17 scores depression was defined as mild in 24(80%) patients, moderate in 5(17%) patients and severe in 1(3%) patient. There were significant between-group differences for the QOLIE-31 overall score and all scores on QOLIE-31 subscales (seizure worry, overall quality of life, emotional well-being, energy/fatigue, cognitive functioning, medication effects and social functioning) which were lower for the patients with comorbid depressive disorder. A moderate correlation was found between the presence of interictal depressive disorder and lower scores for QOLIE-31 overall score and overall quality of life, emotional well-being, energy/fatigue and social functioning. Conclusions: Comorbid depressive disorder is relatively common in people with epilepsy resulting in significant reduction of the quality of life of the affected patients. These data clearly highlight the need to better appreciate its importance in the overall treatment plan of these patients.