Prevalence of depressive symptoms and their impact on quality of life in patients with drug-resistant focal epilepsy (IMDYVA study)

BACKGROUND Drug-resistant epilepsy (DRE) is usually related to focal epilepsy (FE) and is present in up to 30% of patients. Several studies have found high rates of depressive symptoms and poor health related quality of life (HRQOL) in DRE patients but little information is available on these aspects for Spain. OBJECTIVE To determine the prevalence of depressive symptoms in a cohort of Spanish patients with DRE and evaluate their HRQOL in comparison with patients with controlled FE (CFE). METHODS This observational cross-sectional study analyzed FE patients, with and without DRE, recruited from different Spanish neurology outpatient clinics. Presence of depressive symptoms was assessed using the Montgomery-Asberg Depression Rating Scale (MADRS) and the Beck Depression Inventory-II (BDI-II). HRQOL was evaluated using the Quality of Life in Epilepsy Inventory (QOLIE-31). RESULTS 515 patients (DRE = 248) were included. Mean (SD) age was 44.3 (15.4) years and 50.5% were male. Overall, 15.9% had a previous diagnosis of depressive symptoms (DRE = 22.6%; CFE = 9.7%, p < 0.001). Depressive symptoms was observed in 62.1% [95% CI 56.1-68.1] and 64.8% [58.8-70.7] of DRE patients using MADRS and BDI-II, respectively, compared to 32.6% [27.0-38.2] and 37.2% [31.4-43.0] in the CFE group (p < 0.001). Depressive symptoms was associated with poorer HRQOL. Multivariate modeling showed that presence of depressive symptoms on the MADRS or BDI-II had the greatest impact on mean QOLIE-31 scores. CONCLUSIONS Compared to other studies, the rate of depressive symptoms was high (60% in DRE and 30% in CFE patients). MADRS and BDI-II showed a positive correlation. Prior to the study, depressive symptoms were underdiagnosed in a large proportion of patients. Clinical diagnosis of depressive symptoms and not seizure frequency was associated with poorer mean QOLIE-31 scores.