The North Carolina Dissociation Index: A Measure of Dissociation Using Items From the MMPI-2

The development of a new measure of dissociation using items from the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) is described. In Experiment 1,525 college students were administer ed a measure of hypnotic susceptibility and completed several specialized measures of dissociation or dissociation-like experiences. The new measure, the North Carolina Dissociation Index (NCDI), demonstrated adequate internal consistency and good convergent validity. In Experiment 2, the NCDI demonstrated adequate internal consistency and test-retest reliability with a different sample of college students. Moreover, NCDI scores showed a relatively strong correlation with an interview-based measure of dissociative symptoms. In addition, a small sample of students with dissociative disorders had significantly higher NCDI scores than students with anxiety disorders and normal control subjects. In Experiment 3, 19 gang combat veterans were administered a semi-structured diagnostic interview and the MMPI-2, Subjects who were diagnosed with Posttraumatic Stress Disorder (PTSD) scored significantly higher on the NCDI than subjects who did not have PTSD. The NCDI is intended primarily as a tool in settings where the MMPI-2 is routinely administered.