Factor Analysis and Validation of the Disturbing Dream and Nightmare Severity Index in an Inpatient Sample

Study Objectives The Disturbing Dream and Nightmare Severity Index (DDNSI) has been used widely in research and clinical practice without psychometric evidence supporting its use in clinical samples. The present study aimed to explore and confirm the factor structure of the DDNSI in an inpatient sample. We also sought to test the measure's construct validity.