Validation of the Russian version of neurological disorders depression inventory for epilepsy (NDDI-E)

Abstract

Objective: To translate and validate the English version of the Neurologic Depression Disorders Inventory in Epilepsy (NDDI-E) into the Russian language as an instrument for rapid detection of major depressive episodes (MDE) for patients with epilepsy (PWE) from Russian Federation.

Methods: One hundred and 75 consecutive PWE were included in the study. All patients were assessed with Mini-International Neuropsychiatric Interview (MINI 6.0.0), Hospital Anxiety and Depression Scale (HADS) and the Russian version of NDDI-E. Chi-square, Fisher's exact and Mann-Whitney tests were used to compare PWE with and without MDE. We analyzed internal structural validity, external validity, and receiver operator characteristics.

Results: None of the participants had any difficulties in understanding the questions of NDDI-E. The internal consistency of the inventory was satisfactory (Cronbach's ά = 0.856). Correlation between the NDDI-E and the HADS scores was moderate (r = 0.64, P < 0.001), indicating acceptable external validity. NDDI showed good capacity to detect MDE, with area under the curve of 0.919 (95% CI = 0.868-0.955; standard error: 0.019; P < 0.001). An optimal cut-off point with the highest Yuden's index (J = 0.699) was > 12. At this point NDDI-E showed sensitivity of 88.16% (95% CI = 78.7%-94.4%), specificity of 81.82% (95% CI = 72.8%-88.9%), positive predictive value of 59.3% (95% CI = 48.8%-69.0%), negative predictive value of 95.8% (95% CI = 92.5%-97.7%).

Conclusion: Russian version of NDDI-E is an affordable and fast screening tool with a good combination of sensitivity and specificity.

Keywords: Depression screening; Epilepsy; Hospital Anxiety and Depression Scale; Major depressive episode; Mini-International Neuropsychiatric Interview; The Neurological Disorders Depression Inventory for Epilepsy.