Spanish Translation and Psychometric Evidence of the Nightmare Disorder Index (NDI) in Adults from the General Population
European Journal of Investigation in Health Psychology and Education October 27, 2025 Jonatan Baños-Chaparro, Rulman Andrei Franco-Jimenez, Tomás Caycho‐Rodríguez et al.
The Nightmare Disorder Index (NDI) was translated into Spanish and validated with 507 Peruvian adults (66.7% women). The scale demonstrated adequate reliability and validity, with invariance across sex and significant associations with depressive symptoms, generalized anxiety, and suicidal ideation. Item 3 showed the highest discrimination and information, and the scale was accurate at higher levels of nightmare severity. The NDI is recommended for assessing nightmares in professional practice and research with the adult general population.