A proposal for augmenting the measurement of index events in PTSD assessment using event centrality.

Standard practice in assessing and diagnosing posttraumatic stress disorder (PTSD) entails identifying a single "worst" index event as the basis for symptom inquiry. Determining a single event can be challenging for clinicians and clients when multiple traumas are considered equally distressing. Additionally, it can be difficult to distinguish potential index events based on distress given the cumulative effect of repeated trauma exposure. This calls for the development of approaches that build on existing selection methods (e.g., worst event method). In this article, we propose an innovative approach for identifying and measuring index events that utilizes the construct of event centrality to expand the parameters by which index events are selected. Event centrality assesses the degree to which traumatic events are perceived as integral to one's personal identity and worldviews. Given its role in the etiology and maintenance of PTSD symptoms, this construct also approximates the emotional impact of trauma. Incorporating validated measures of event centrality into PTSD assessments would provide an objective strategy for identifying index events in a way that may increase the reliability of diagnosis. Our proposed strategy may also have a positive impact on the therapeutic process and treatment outcomes.