Screening for major depressive episodes in Japanese patients with epilepsy: validation and translation of the Japanese version of Neurological Disorders Depression Inventory for Epilepsy (NDDI-E).

We validated and translated into Japanese the English version of the screening instrument Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) to identify major depressive episodes in patients with epilepsy. A total of 159 Japanese subjects with epilepsy underwent a psychiatric structured interview with the Japanese version of the Mini International Neuropsychiatric Interview (M.I.N.I.-J) followed by completion of the Japanese version of NDDI-E (NDDI-E-J). Twelve participants met the M.I.N.I.-J criteria of current major depressive episode. Participants had no difficulties completing the NDDI-E-J. Its Cronbach's alpha coefficient was 0.83 and a cut-off score greater than 16 provided a sensitivity of 0.92, a specificity of 0.89, and a negative predictive value of 0.99. The NDDI-E-J appears to be useful for primary care clinicians to screen for major depressive episodes in epilepsy patients. Routine use of this brief and self-administered instrument in busy clinical settings will likely improve management of depression in Japanese individuals with epilepsy.