Objectives: The aim of this study was to compare the efficacy of the Neurological Depressive Disorders Inventory for Epilepsy (NDDI-E) and the depression component of the Hospital Anxiety Depression Scale (HADS-D) for identifying depression and suicide risk in adults with epilepsy.
Methods: A total of 147 (87 female [59% ]) outpatients attending a tertiary epilepsy center in Sydney Australia completed the NDDI-E and HADS-D. They then completed the depression and suicide sections of the Mini International Neuropsychiatric Inventory (MINI) with a clinician blind to symptom measure scores. Receiver operator characteristic analysis was performed for the clinical cutoff scores for depression on the NDDI-E ≥ 15 and HADS-D ≥ 8 to identify MINI-determined depression and suicidality.
Results: The NDDI-E indicated strong sensitivity (84%) and acceptable specificity (78%), whereas the HADS-D had poor sensitivity (42%) but good specificity (97%) for identifying depression. For identifying suicide risk, the NDDI-E indicated strong sensitivity (81%) and reasonable specificity (66%), whereas the HADS-D had poor sensitivity (43%) but acceptable specificity (90%). Area under the curve comparisons for these measures were not significant.
Conclusion: In clinical practice, it is essential that screening measures have the highest possible sensitivity values to limit the chances of false-negative results. In accordance with these guidelines, the NDDI-E was a superior screening measure compared with the HADS-D. Our results demonstrate the efficacy of the NDDI-E for identifying both major and minor depression and serious suicide risk. The poor sensitivity of the HADS-D suggests that it should not be used as a screen for depression or suicidality in adults with epilepsy.