BPD vs C-PTSD: What's the Difference?

There’s something to be said of the controversy around borderline personality disorder and complex post-traumatic stress disorder. Is one correct and the other invalid? Do they exist separately from one another? Do they coexist and influence one another? For those who are curious about the studies, here is one research effort to look into:

Distinguishing PTSD, Complex PTSD, and Borderline Personality Disorder: A latent class analysis

Let’s begin with the DSM-5-TR, the tool used by clinicians and medical professionals for diagnoses. It is not a perfect tool. It comes with many barriers and shortfalls due to the human hands who write it. It’s important to remember that social and cultural influences are deeply embedded in all that we do, which includes those within the scientific community. It is a tool that is intended to create a common ground of understanding and agreement for treatment. I’ll come back to this later.

Here are some things to consider. Let’s start where overlap occurs between BPD and C-PTSD: self-harm, suicidality/suicide attempts, struggles with intimacy/relationships, dissociative symptoms, dysregulated emotions, anger outbursts, interpersonal sensitivity, impulsivity, and the use of impulsive coping skills such as self-harm and substance use.

The nuance in the differences is where the lens of a seasoned clinician can identify the variables.

  • Individuals who have C-PTSD and not BPD tend to have more stable interpersonal relationships; they are often longstanding and are not generalized with the explosive ups and downs of idealization/devaluation. C-PTSD will often avoid relationships and intimacy and have a preference for social withdrawal.
  • Individuals with C-PTSD generally have a stable negative view of self associated with their traumatic core beliefs; there is not much fluctuation in "identity uncertainty" outside of their trauma. BPD’s experience with "identity uncertainty" is more deeply rooted in their experience of themselves and the world around them.
  • Individuals with C-PTSD can have familiar fears of abandonment and beliefs “I leave others before they leave me”; however a common misconception is that fear of abandonment is a criterion for BPD. This is incorrect. BPD will engage in frantic efforts to avoid abandonment, such as texting/calling repeatedly, blocking pathways and doors, taking others’ possessions, etc.
  • Affect dysregulation in BPD can also include dysregulation of positive affect (or the painful high highs), where C-PTSD has a consistent baseline of negative mood and dysregulation of negative affect.
  • Individuals with BPD tend to have more severe and pervasive impulsivity compared to C-PTSD. C-PTSD tends to lean more towards inhibited than impulsive, such as substance use, which may appear to be impulsive to those on the outside, is a maladaptive coping skill for trauma management. A note worth making here is the presence of neurodivergence, such as ADHD, can confound this concept and may be less useful information for this population.
  • Individuals with C-PTSD most commonly do not meet 5/9 criteria for BPD when the clinician deeply explores the substantiation of the criteria used in the DSM as mentioned with very different interpersonal difficulty patterns.

Now that we’ve gone through that, let me bring back the mention of the DSM-5-TR used to diagnose these disorders. It’s important to consider the functionality of a diagnosis. For a clinician, it can be beneficial to guide treatment options. Insurance uses it for reimbursement of payment for services. For the client, it can be helpful for insight and understanding of self; it can help communication and connection; and it can help guide their treatment options, as well. However, it could function negatively. It can be a source of stress, stigma, and shame.

As a clinician seasoned in treating both BPD and C-PTSD, work can be done with or without the diagnosis. Some people can strongly identify with one or the other; or both. If a client wants or needs to know, we can explore it together and reach clarity. If not, then we won’t fuss about the label and simply work together to achieve healing and a more congruent lifestyle; one without shame.