4 Behaviors That Point To Borderline Personality Disorder As More Than “Just” Personality
Exploring why BPD should be rebranded as a trauma-related disorder.

Current research suggests as many as 3.5% of adults in the general population are living with a diagnosis of Borderline Personality Disorder (BPD), with upwards of 18% of adults diagnosed with BPD in clinical populations. According to the International Classification of Diseases, 11th Edition (ICD-11), there are also estimates of as many as 36% of adults currently seeking mental health treatment for complex Post-Traumatic Stress Disorder (cPTSD).
BPD and cPTSD often occur comorbidly, with upwards of 70% — 80% of persons diagnosed with BPD also meeting the criteria for a trauma-based disorder, such as cPTSD. These findings suggest that overlaps between the two disorders may support rebranding BPD from a “personality” disorder to a trauma-related disorder. Because symptoms associated with BPD are not limited to “just” personality traits (i.e. fixed beliefs, thoughts, feelings, ideals, values), to suggest that BPD as a “fixed” cluster of personality traits oversimplifies the disorder.
This mindset also minimizes a person’s lived experiences and their potential effects on that person’s behavior, which includes the effects of trauma a person may be living with.
What does this suggest?
That behavior may provide the answer to unpacking this ongoing debate.
Origins of BPD
Not “everyone” with a diagnosis of BPD has experienced chronic adverse experiences in their childhood. Some people with diagnoses of BPD will vehemently deny having experienced childhood trauma, while others may have experienced isolated incidences of trauma in adolescence or their adult lives. Still, others may simply be more hardwired for the disorder, as genetics and biological research suggest. However, this should not suggest that the disorder does not affect a person on a traumatic level.
Yet, one shortcoming in genetics studies of BPD is that they typically leave out possible effects of inter-generational trauma, bullying, or other childhood traumatic situations, including attachment or developmental trauma as possible risk factors.
On the flipside, where genetics studies leave off, environmental studies of BPD pick up the slack. Factors that have been extensively researched as a proposed origin of BPD include invalidating environments, attachment injuries formed in early childhood, abuse, neglect, abandonment, and relational trauma — all are factors supporting BPD as originating from environmental (behavioral conditioning) contingencies.
With statistics suggesting as many as 80% of people diagnosed with BPD as having experienced some form of trauma in their lives (especially in early life), this tends to tilt more to environmental influences. Hence, severe, chronic, and traumatic stress typically plays a key role in the development of both BPD and cPTSD.
The difference?
CPTSD includes experiences of profound and chronic trauma in its core definition, whereas BPD focuses more on personality traits, self-identity, and fears of abandonment.
Unpacking Key Similarities
Psychologists are trained to assess and diagnose based on the most recent version of the DSM, which is currently the DSM-V-TR. Granted, this tool is not perfect, and many psychologists are in agreement that some — if not most — Cluster B personality disorders have strong correlations with early traumatic experiences including BPD. However, what complicates things is that cPTSD is not formally recognized in the DSM-V-TR, but is formally recognized in the ICD — 11, suggesting that a person who may receive a diagnosis of BPD or PTSD, should in fact be considered for cPTSD.
There are many behaviors with high levels of enmeshment between BPD and cPTSD, adding support that BPD should be considered for rebranding as a disorder of stress, not personality.
Four of these behaviors include:
Disconnection
Disconnection caused by trauma is where we become “separated” from our body sensations and often feel numb, or empty. These feelings can lead to feeling hopeless, or even suicidal ideation. For example, we may push others away, feel like no one understands us, or be “stuck in our head” with patterns of overthinking and ruminating. Or, we may be prone to tuning out and dissociating if a situation becomes too overwhelming for us. This is something that trauma experts identify as self-protective, which allows us to temporarily disconnect from chronic stress.
Yet, in BPD, disconnection is often shamed and identified as feelings of emptiness originating from limited self-awareness and self-identity. These experiences can lead to feelings of hopelessness, or even suicidal ideation. This may include changing jobs or relationships often, feeling misunderstood, pushing others away, chronic feelings of loneliness, or a pattern of meaningless and superficial relationships to try and feel less empty inside.
Impulsivity
With trauma, impulsivity is assessed as “fight or flight” responses that trigger impulsive behavior in order to escape or avoid situations or experiences that may be triggering to a person. We may impulsively lash out (fight response), or arbitrarily leave a relationship or situation (flight response). Other impulsive behaviors commonly include self-medicating, or repetition compulsion, where there is a pattern of subconsciously turning to relationships that ultimately trigger unhealed attachment wounding.
With BPD, feelings of disconnection often trigger impulsive or addictive behavior patterns and are identified as toxic, self-injurious, self-serving, and lacking in empathy. Similar to impulsivity in trauma, impulsivity in BPD is also done spontaneously, is typically unplanned and arbitrary, and used as a way of helping to regulate feeling overwhelmed, unsafe, or in distress. Yet, in BPD the same type of impulsive behaviors are villainized as a core symptom of the disorder, instead of a trauma response associated as self-protective.
Attachment Trauma
At its core, cPTSD is defined as prolonged, severe, and chronic trauma, which often includes childhood attachment trauma. Attachment trauma is defined as a disruption of critical bonding between caregiver and infant originating from ongoing abuse and/or neglect. The result is that an infant grows to develop an insecure attachment style, which can include: Anxious, Avoidant, or Fearful-Avoidant (“Disorganized”).
There is much research supporting Fearful-Avoidant attachment as synonymous with symptoms and behaviors of both BPD and cPTSD.
When it comes to Fearful-Avoidant attachment, many experienced profound trauma as young children which included: unpredictable, violent, and unsafe environments where their primary caregiver(s) were also a source of fear. Children who grow up in these conditions typically learn the world and people as unsafe. Many become adults who find themselves in repeated cycles of toxic relationships (often with narcissists), and histories of traumatic bonds in an attempt to find validation, love, safety, and belonging.
When exploring Fearful-Avoidant attachment through a trauma lens, it de-stigmatizes the behaviors associated with it as the outcome of growing up in abusive conditions, often where the child was unwanted and unloved. Yet, similar behaviors can be seen in BPD, but are villainized as a product of “erratic”, “emotionally unstable”, and “neurotic” behavior, where the assumption is that they cause the abuse they receive.
Emotional Dysregulation
When looking at this through a trauma lens, these kinds of behaviors are documented as excessive or intense reactions, often with explosive outbursts when feeling “triggered” (i.e. feeling unsafe). These behaviors are usually paired with an inability to self-soothe and regulate their emotions, or in becoming “numb” and shutting down, especially in relationships that trigger feelings of vulnerability. People with extensive histories of childhood trauma often feel unsafe in their daily lives, and can easily be triggered into re-experiencing their trauma. For example, feeling “trapped” or in too close proximity to someone may trigger experiences of being unable to escape abuse in our childhood.
However, very similar patterns are seen in people with a BPD diagnosis, yet these behaviors are pathologized as “unstable” and “erratic”. For example, because many with a BPD diagnosis can find themselves in romantic relationships with those with NPD, common behavior patterns that trigger feeling unsafe or vulnerable may include: abusive relationships that were conditioned as “normal” from childhood, getting “hooked” into familiar childhood patterns of savior à perpetrator à victim roles, or unmet needs for validation being “met” through idealization.
Where do we draw the line?
While there are significant overlaps between cPTSD and BPD, there are also a couple distinct differences that can help separate the two.
For example, those with BPD are prone to severe and overwhelming fears of abandonment that can trigger impulsive (self-preserving) behavior where they arbitrarily leave a relationship at the first sign of fearing abandonment. Fears of abandonment are typically not seen in people with cPTSD. On the contrary, many will choose to be alone as safer than engaging in a relationship. This is perhaps most common with those who have histories of profound childhood trauma, including abuse and neglect.
Another key difference between the two is that people with BPD struggle with understanding who they are at their core — with limited self-identity — whereas people with cPTSD have a more solid sense of self-identity, but struggle with deep and negative feelings of self-worth.
Given the overlaps between the two disorders, this could suggest that re-categorizing BPD from a disorder of personality to a trauma-related disorder is worthy of further exploration. True, not everyone with a diagnosis of BPD has a history of profound childhood trauma as seen in cPTSD. However, the fact that BPD is one of the most stigmatized disorders can be traumatic in itself for anyone living with it.
Linehan, M. M. (2018). Cognitive-behavioral treatment of borderline personality disorder. Guilford Publications.






