Beliefs Related to Diagnosing BPD and Complex PTSD

There has been speculation that Borderline personality disorder (BPD) and Complex post-traumatic stress disorder (Complex PTSD) are the same disorder or represent separate disorders on a broader trauma spectrum (Frost et al., 2020; Lewis & Grenyer, 2009). BPD and Complex PTSD share several symptoms but differ in their presentation (Ford & Courtis, 2021). Because the two disorders present so similarly, it could be that clinicians have difficulty differentiating them, leading to misdiagnosis (Miller, 2014). This study examined clinicians’ diagnostic decision-making and stigma toward BPD and Complex PTSD. Participants (N = 426) completed an online survey where they diagnosed a written case vignette and completed measures of their familiarity with each disorder, stigma, and symptom importance for their diagnosis. Results indicated that clinicians were significantly less familiar with BPD than with Complex PTSD; however, only familiarity with Complex PTSD predicted diagnostic decisions. Higher familiarity with BPD was associated with lower stigma toward BPD, whereas familiarity with Complex PTSD predicted lower stigma for both disorders. Stigma levels were significantly higher for BPD than for Complex PTSD, but only stigma toward Complex PTSD predicted diagnosis. Demographic factors (e.g., gender, profession, degree, theoretical orientation) did not influence diagnosis or stigma. No significant evidence of anchoring bias was found in diagnostic decisions. However, symptom ranking strongly influenced diagnosis, with clinicians more likely to assign a diagnosis based on symptoms they associated with BPD or Complex PTSD. BPD stigma influenced rankings of BPD symptoms, whereas Complex PTSD stigma affected rankings across all symptom categories. These findings suggest that familiarity and stigma play crucial roles in shaping diagnostic decisions and highlight the need for improved clinician training to mitigate biases and enhance diagnostic accuracy.