PTSD: National Center for PTSD
Impact of Event Scale - Revised (IES-R) for DSM-IV
Impact of Event Scale - Revised (IES-R) for DSM-IV
Description
NOTE: This measure was based on DSM-III (IES) and DSM-IV (IES-R) criteria for PTSD. See a list of all measures, including those updated to DSM-5.
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 7 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. The IES-R has not been updated to match the DSM-5, so it does not include items to full assess negative alterations in cognition and mood, for instance. 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.
Scoring
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.
Sample Item
"Any reminders brought back feelings about it." (Respondents rate their degree of distress during the past 7 days on a 5-point scale.)
Versions
The 15-item IES is the original scale but is missing DSM-IV 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). Guilford. (NOTE: Includes measure in its entirety.)
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
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.
