Psychometric Properties of the Nightmare Distress Questionnaire in Veterans with Posttraumatic Nightmares.

OBJECTIVES

The study examined the psychometric properties of the Nightmare Distress Questionnaire (NDQ) in veterans with a provisional posttraumatic stress disorder (PTSD) diagnosis and trauma-related nightmares.

METHOD: Participants were 659 Australian Defence Force veterans who completed online questionnaires for a larger study investigating military-civilian transition. Analyses included exploratory factor analysis, and evaluation of internal consistency and convergent and divergent validity in a subsample of 191 veterans meeting provisional PTSD diagnostic criteria and endorsing trauma-related nightmares. An independent samples t-test assessed discriminant validity, comparing NDQ scores between participants with (n = 280) and without (n = 379) a provisional PTSD diagnosis.

RESULTS

Principal-axis factoring suggested a one-factor solution comprising 10 items that explained 51.46% of the variance in nightmare distress. The NDQ demonstrated strong internal consistency, and correlations with validated measures supported convergent and divergent validity. NDQ scores were significantly higher for veterans with a provisional PTSD diagnosis.

CONCLUSIONS

Findings offer initial evidence of the NDQ's validity and reliability to assess trauma-related nightmare distress among veterans. We provide novel insights into the NDQ's utility for researchers and clinicians working with veteran populations, including its ability to differentiate veterans based on PTSD symptomatology.