The PDS is a 49-item self-report measure recommended for use in clinical or research settings to measure severity of PTSD symptoms related to a single identified traumatic event. The PDS is unique in that it assesses all of the DSM-IV criteria for PTSD (i.e., Criteria A – F) and inquires about the past month (time frame can be adjusted for different uses). Thus, in addition to measuring the severity of PTSD symptoms (Criteria B, C, & D), it also inquires about the experience of a Criterion A traumatic events, about duration of symptoms (Criterion E), and the effects of symptoms on daily functioning (Criterion F).