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Post-Traumatic Stress Disorder

Is It Borderline Personality Disorder or Is It Really Complex PTSD?

Exploring the similarities and differences.

Borderline personality disorder (BPD) is a pervasive and lifelong mental disorder that affects interpersonal relationships, mood, and behavior. Those diagnosed with BPD often struggle with an unstable self-identity and self-image, difficulty in regulating their emotions, impulsive and self-sabotaging behavior, a fear of abandonment, feelings of emptiness, and a pattern of highly unstable relationships where idealization and devaluation are common.

Although those who develop BPD may have a history of child abuse or neglect, the causes of BPD are often not fully understood. However, some research suggests links to genetics with a family history or a biological predisposition to the disorder, while other research supports an environmental link.

Complex PTSD, or cPTSD, is a subset of PTSD. Whereas PTSD is a fear-based disorder, cPTSD is often referred to as a shame-based disorder originating from a history of chronic, and long-term exposure to traumatic events such as ongoing severe child abuse or long-term relationship abuse.

Those who have experienced repeated trauma at a young age and/or where escape from the situation was not possible are at a greater risk for developing cPTSD, such as children who cannot escape their home environment. Symptoms include flashbacks of the events, fear, despair, shame, chronic devaluation of self, terror, and avoidance of socialization or relationships. Unfortunately, those who have experienced severe ongoing trauma in childhood are at an increased risk for being re-traumatized in adulthood—especially in romantic relationships—thus increasing their risk of developing cPTSD or a worsening of existing symptoms.

Similarities Between BPD and cPTSD

BPD and cPTSD often get confused because of their similar and often overlapping behavior and affective patterns. Both often come with significant overall emotional distress and/or emotional “triggers,” suicidal thoughts, dissociation, flashbacks, anxiety, and depression. Even with sophisticated diagnostic criteria, there are behavioral and affective overlaps between the two disorders which can complicate whether symptoms are exclusive to one disorder or a combination of the two.

Additionally, both diagnoses struggle with issues of negative self-concept, difficulties in regulating their emotions—including outbursts of crying or rage—and significant interpersonal relationship issues. Both BPD and cPTSD may be dually diagnosed in a person where symptoms can range from high to low in one, or both disorders.

Key Differences Between BPD and cPTSD

  • While both disorders may experience symptoms associated with fear within relationships, one distinguishing factor seen in BPD that is not often seen in cPTSD is a fear of abandonment. Those with cPTSD, however, may avoid relationships based on feeling somehow unlovable or undeserving because of the abuse they endured, which can overlap with similar feelings experienced in BPD. Similarly, those with cPTSD often avoid relationships altogether or push others away as unsafe or threatening; these behaviors may be confused as a fear of abandonment seen in those with BPD.
  • Those with cPTSD may often feel shame and blame themselves for their interpersonal problems—a symptom that is also similar to the experiences of those with BPD. However, another key difference is that those with cPTSD usually do not self-harm; this is a more common behavior seen in BPD, where stressors in interpersonal relationships may trigger episodes of self-harming behavior. This may include suicidal ideation or a suicide attempt.
  • Another key difference between the two is that whereas both may feel relationships are seen as unsafe or threatening, a person with cPTSD may often choose to avoid intimacy or relationships altogether. A person with BPD, on the other hand, may struggle with being alone and may use relationships to prevent feelings of loneliness or abandonment.
  • While both those with BPD and cPTSD struggle with emotional regulation and often experience outbursts of anger or crying, those with cPTSD may experience emotional numbing, emptiness, or detachment from emotions.
  • Additionally, while both those with cPTSD and BPD can struggle with a solid self-concept, those with BPD often struggle with an understanding of who they are at their core. They may change their interests or hobbies depending on who they associate with because of a limited sense of self-identity. On the other hand, those with cPTSD have an understanding and awareness of who they are and have a more stable self-identity. However, they struggle with feeling "damaged" or deserving of the pain they’ve suffered and carry misbeliefs about themselves as unworthy of love or undeserving of happiness. These experiences impact relationships, which may be confused as a problem with self-identity or self-awareness.
  • Lastly, while both those with BPD and cPTSD often struggle with traumatic pasts, with successful treatment those with cPTSD may experience less emotional reactions or behavioral disruptions over time by engaging in calming strategies or redirecting their energy away from an emotional stressor to reduce symptoms associated with panic attacks.

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Dijke, A., et al. (2018). Affect dysregulation, psychoform dissociation, and adult relational fears mediate the relationship between childhood trauma and complex posttraumatic stress disorder independent of the symptoms of borderline personality disorder. European Journal of Psychotraumatology, 9, 1 – 14.

Ford, J. D. (2017). Complex trauma and complex posttraumatic stress disorder. Handbook of Trauma Psychology, 1,(15), 281- 305.

Ford, J.D., et al. (2014). Complex PTSD, affect dysregulation, and borderline personality disorder. Borderline Personality Disorder and Emotion Dysregulation, 1(9), 1 – 17.

Frost, R., et al. (2020). Distinguishing complex PTSD from borderline personality disorder in individuals with a history of sexual trauma: A latent class analysis. European Journal of Trauma & Dissociation, 4, 1 – 8.

Jowett, S., et al. (2019). Differentiating symptom profiles of ICD-11 PTSD, complex PTSD and borderline personality disorder: A latent class analysis of a traumatized sample. Personality Disorders, Theory, Research and Treatment, 11(1), 36 – 45.

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