Ultra-short screening instruments for major depressive episode and generalized anxiety disorder in epilepsy: The NDDIE-2 and the GAD-SI

J Affect Disord. 2017 Mar 1:210:237-240. doi: 10.1016/j.jad.2016.12.038. Epub 2016 Dec 27.


Background: Systematic screening is recommended for major depressive episode (MDE) with the Neurological Disorders Depression Inventory for Epilepsy NDDI-E, 6 items and generalized anxiety disorder (GAD) with the GAD 7 items in patients with epilepsy (PWE). Shorter versions of the NDDI-E and the GAD-7 could facilitate increased screening by busy clinicians and be more accessible to patients with mild cognitive and/or language impairments.

Methods: The effectiveness of ultra-short versions of the NDDI-E (2 items) and the GAD-7 (the GAD-2, 2 items, and the GAD-SI with a single item) in comparison with the original versions were statistically tested using ROC analysis.

Results: ROC analysis of the NDDIE-2 showed an AUC of 0.926 (p<0.001), a sensitivity of 81.82% and a specificity of 89.16%, without significant difference with the NDDI-E (z=1.582, p=0.11). ROC analysis of the GAD-SI showed an AUC of 0.872 (p<0.001), a sensitivity of 83.67% and a specificity of 82.29%, without significant difference with the GAD-7 (z=1.281, p=0.2). The GAD-2 showed poorer psychometric properties.

Limitations: The limitation is the use of data from previously reported subjects in a single language version, the NDDIE-2 that lacks detection of dysphoric symptoms in comparison with the NDDIE-6 and the GAD-SI that exhibited a more than 10% lower sensitivity than the GAD-7.

Conclusions: This study highlights the potential utility of the NDDIE-2 and the GAD-SI as ultra-short screening tools for MDE and GAD respectively in PWE. Further studies in a larger population, including multi-lingual versions, could be a valuable next step. However, the brevity and simplicity of this tool could be an advantage in PWE who present cognitive difficulties, especially attentional or language deficits.

Keywords: Epilepsy; Generalized anxiety disorder; Major depressive disorder; Psychiatric comorbidity; Screening tool.

MeSH terms

  • Adult
  • Anxiety Disorders / diagnosis*
  • Brief Psychiatric Rating Scale*
  • Depression / diagnosis
  • Depressive Disorder, Major / diagnosis*
  • Depressive Disorder, Major / psychology
  • Epilepsy / psychology*
  • Female
  • Humans
  • Language Disorders
  • Male
  • Middle Aged
  • Psychometrics / instrumentation*
  • ROC Curve
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Stress Disorders, Traumatic, Acute