The relative impact of anxiety, depression, and clinical seizure features on health-related quality of life in epilepsy

Purpose: To determine the independent effects of depression and anxiety on health-related quality of life (HRQOL) in epilepsy as well as the relative explanatory power of psychiatric comorbidity compared with demographic and clinical epilepsy variables (e.g., seizure frequency, severity, and chronicity). Methods: Subjects (n = 87) with temporal lobe epilepsy completed self-report measures of depression, anxiety, HRQOL, and seizure severity. Information was derived regarding subjects' seizure frequency, duration, and treatment. HRQOL status (QOLIE-89) was examined in relation to self-reported symptoms of anxiety and depression, clinical seizure features, and demographic characteristics. Results: Depression and anxiety were independently associated with reduced HRQOL. Psychiatric comorbidity explained more variance in HRQOL than did combined groups of clinical seizure or demographic variables. Although weaker in explanatory power than psychiatric comorbidity, several epilepsy factors were nonetheless significantly related to HRQOL, including seizure frequency, severity, and chronicity. Conclusions: Interictal anxiety and depression exert independent adverse effects on HRQOL. In addition, frequent, severe, and chronic seizures reduce HRQOL, but appear less powerful predictors of HRQOL than interictal psychiatric symptoms. Recognition and treatment of comorbid depression and anxiety is an important consideration in improving quality of life in epilepsy.