2.7.1. Primary outcome measure – standardized PTSD interview (PSSI-5)

We will use the PTSD Symptom Scale-Interview Version (PSSI-5) to assess posttraumatic stress symptoms [52]. This interviewer-administered 20-item scale rates each of the DSM-5 symptom criteria on a 0–3 scale of frequency and/or severity. To meet criteria for PTSD, individuals must endorse at least one statement from each of the following symptom clusters: “Re-experiencing” and “Avoidance”; and at least two statements from the following symptom clusters: “Changes in Cognition and Mood” and “Increase Arousal and Reactivity”. The PSSI-5 is a reliable and valid scale; it is sensitive to treatment effects and is highly correlated with the Clinician Administered PTSD Scale, another widely used PTSD interview assessment [53].