The PSS-I is a 17-item semi-structured interview that assesses the presence and severity of DSM-IV PTSD symptoms related to a single identified traumatic event in individuals with a known trauma history. The PSS-I takes about 20 minutes to administer and can be administered by lay interviewers trained to recognize the clinical picture in traumatized persons. Each item is assessed with a brief, single question. There are no probes or follow up questions.
Interviewees are asked about symptoms they have experienced in the "past two weeks." This time frame differs from the standard one month time frame of other measures. For each item, the interviewer assigns a rating to reflect a combination of frequency and severity (from O = "not at all" to 3 = "5 or more times per week/very much").
Have you had recurrent or intrusive distressing thoughts or recollections about [the event]?
0 = not at all
1 = Once per week or less/a little bit
2 = 2-4 times per week/somewhat
3 = 5 or more times per week/very much
Foa, E., Riggs, D., Dancu, C., & Rothbaum, B.(1993). Reliability and validity of a brief instrument for assessing post-traumatic stress disorder. Journal of Traumatic Stress, 6, 459-474.
Foa, E & Tolin, DF (200). Comparison of the PTSD Symptom Scale-Interview Version and the Clinician-Administered PTSD Scale. Journal of Traumatic Stress, 13, 181-191.
Edna Foa, PhD
Department of Psychiatry
University of Pennsylvania
3535 Market Street 6th Floor
Philadelphia, PA 19104
Phone: (215) 746-3327
Measures availability: Information on measures is available to everyone. However, the assessment tools themselves can only be distributed to qualified mental health professionals and researchers. We maintain measures developed by affiliated staff of the National Center for PTSD.