“To a large degree, a particular collision of genes and temperament with a suboptimal or hostile environment may explain the development of borderline personality disorder.” ― Dolores Mosquera
Why does BPD occur?
The causes of BPD are not yet fully understood. However, it is likely from a combination of: genetics, high emotional sensitivity, drug and alcohol use, early and long environment that seems invalidating, stress from financial, school, work, relationship or family issues.
BPD is five times as likely among first-degree relatives of those with BPD than the general population. Genetic abnormalities appear to affect the proper functioning of brain pathways that serve functions such as: emotion information processing, impulse control, and cognitive responses such as how we understand and respond to the world and ourselves.
There is no single gene that determines BPD, but the combination of inherited genes may increase risk of BPD and related disorders, such as bipolar disorder, depression, substance use disorders, attention deficit hyperactive disorder, and post-traumatic stress disorder. A child with such vulnerabilities may be at risk of developing BPD if the child lives in a triggering environment. However, it’s very difficult to know if BPD symptoms are inherited or from being exposed to behaviours in the home.
Up to 75% of people with BPD have a history of childhood sexual abuse, physical abuse, witnessed domestic violence, or experienced emotional abuse or neglect. People with BPD often come from a background of dysfunctional family relationships. Hence, trauma and suffering of this kind could be a key factor of BPD. It may be that in early life, traumatic memories are blocked out, but the manifestations of ongoing distress and the consequences of emotional, physical or sexual abuse as a young person is profound and emerges in early adulthood. It is important to state that this is not the sole reason why BPD occurs, nor does everyone who experiences early trauma develops BPD. However, due to these findings, some experts have suggested that BPD may be a complex form of post-traumatic stress disorder.
About 75% of people diagnosed with BPD are women. Trauma is gendered because different genders experiences trauma in different ways. Also, others’ display different attitudes to their experiences of trauma so therefore the impact of a traumatic experience is influenced by a person’s social context. It is important to note that not everyone who develops BPD has experienced trauma as a child, nor does everyone who experiences early trauma develops BPD.
The brain of a person with BPD is on high alert. Experiences are felt more intensely and stressful than how others would feel. The fight-or-flight response is more sensitive and once it is triggered, rational thinking is overwhelmed by survival instincts that can sometimes seem like “child-like” responses. This can occur across a wide range of situations causing significant harm to social, work and family relationships.