Differentiating Complex Posttraumatic Stress Disorder and Posttraumatic Stress Disorder Symptoms Using the Interpersonal Circumplex.

Complex posttraumatic stress disorder (cPTSD) includes core post-traumatic stress disorder (PTSD) symptoms plus disturbances in self-organization (DSO), yet debate continues over whether it is sufficiently distinct from existing diagnostic categories to be considered a separate diagnosis. This study examines the interpersonal characteristics of PTSD, cPTSD, borderline personality disorder (BPD), and level of personality functioning (LPFS) using the interpersonal circumplex. A trauma-exposed sample of 554 adults completed measures of PTSD symptoms (PCL-5, ITQ-PTSD), DSO symptoms (ITQ-DSO), personality pathology symptoms (BSL-23 and LPFS) and interpersonal functioning on the problems and values surfaces. Both the PCL-5 and ITQ-PTSD scales demonstrated similar interpersonal profiles, as did DSO and LPFS (but not BPD). PTSD and BPD symptoms were characterized by cold-dominant interpersonal problems, cold values, and high interpersonal distress. DSO and LPFS symptoms, on the other hand, were characterized by cold-submissive problems and cold/cold-submissive values. Moreover, DSO was associated with significantly higher distress than PTSD but lower distress than BPD. Results provide evidence for DSO as a distinct interpersonal construct from PTSD and BPD and indicate that there is substantial overlap in the interpersonal characteristics associated with DSO and LPFS. These findings support the diagnostic validity of a cPTSD category and suggest that dimensional approaches to personality assessment can enhance differential diagnosis and inform trauma-focused interventions.