A brief self-report measure for frequent distressing nightmares: The Nightmare Experience Scale (NExS).

Both nightmare frequency and nightmare distress have been described as cardinal features of the nightmare experience. However, most previous research has either neglected nightmare distress or measured it separately from nightmare frequency. Based on current nosology of nightmare disorder and recent research findings, the current work conceptualizes the two as representing a single construct, frequent distressing nightmares. Four studies are presented involving a total of 819 university students aimed at the development and examination of a brief scale, the Nightmare Experience Scale (NExS), for measuring frequent distressing nightmares. The NExS demonstrated good internal consistency and test–retest reliability. Validity was supported through a unidimensional factor structure and strong correlations with existing measures of nightmare frequency, nightmare distress, and nightmare intensity, as well as moderate correlations with dream recall frequency, general psychological distress, neuroticism, and posttraumatic stress disorder symptoms. The NExS demonstrated incremental predictive validity of general distress and posttraumatic stress disorder symptoms over and above individual measures of nightmare distress, frequency, and intensity. Moreover, it was able to discriminate individuals who met criteria for nightmare disorder and controls. The results and suggestions for future research are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved)