PTSD: National Center for PTSD

Impact of Event Scale - Revised (IES-R) for DSM-IV

Weiss, & Marmar, 1996

Description

The IES-R is a 22-item self-report measure (for DSM-IV) that assesses subjective distress caused by traumatic events. It is a revised version of the older version, the 15-item IES (Horowitz, Wilner, & Alvarez, 1979). The IES-R contains seven additional items related to the hyperarousal symptoms of PTSD, which were not included in the original IES. Items correspond directly to 14 of the 17 DSM-IV symptoms of PTSD. Respondents are asked to identify a specific stressful life event and then indicate how much they were distressed or bothered during the past seven days by each "difficulty" listed.

Items are rated on a 5-point scale ranging from 0 ("not at all") to 4 ("extremely"). The IES-R yields a total score (ranging from 0 to 88) and subscale scores can also be calculated for the Intrusion, Avoidance, and Hyperarousal subscales. The authors recommend using means instead of raw sums for each of these subscales scores to allow comparison with scores from the Symptom Checklist 90 - Revised (SCL-90-R; Derogatis, 1994). In general, the IES-R (and IES) is not used to diagnosis PTSD, however, cutoff scores for a preliminary diagnosis of PTSD have been cited in the literature.

Sample Item

"Any reminders brought back feelings about it." (Respondents rate their degree of distress during the past seven days.)

Versions

The 15-item IES is the original scale, but is missing hyperarousal symptoms (Horowitz, Wilner, & Alvarez, 1979).

References

Weiss, D. S., & Marmar, C. R. (1996). The Impact of Event Scale - Revised. In J. Wilson & T. M. Keane (Eds.), Assessing psychological trauma and PTSD (pp. 399-411). New York: Guilford. (NOTE: Includes measure in its entirety.)

Additional Reviews

Orsillo (2001) (PDF) p. 267.

Orsillo, Susan M. (2001). Measures for acute stress disorder and posttraumatic stress disorder. In M.M. Antony & S.M. Orsillo (Eds.), Practitioner's guide to empirically based measures of anxiety (pp. 255-307). New York: KluwerAcademic/Plenum. PTSDpubs ID 24368

To Obtain Scale

Daniel Weiss, PhD
Department of Psychiatry
University of California - San Francisco
PO Box 0984-F
San Francisco, CA 94143-0984
Phone: (415) 476-7557

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Measure availability: We provide information on a variety of measures assessing trauma and PTSD. These measures are intended for use by qualified mental health professionals and researchers. Measures authored by National Center staff are available as direct downloads or by request. Measures developed outside of the National Center can be requested via contact information available on the information page for the specific measure.