Borderline personality disorder (BPD) is a serious mental illness characterized by difficulties regulating emotions, impulsive behavior, unstable relationships, and a distorted self-image. While the exact causes of BPD are not fully understood, research suggests that both biological and environmental factors play a role in its development.
Genetic and Biological Factors
There appears to be a genetic component to BPD. People with a first-degree relative with BPD are five times more likely to develop the disorder themselves. Specific genes that may be linked to BPD include the serotonin transporter gene and the brain-derived neurotrophic factor gene.
In addition to genetics, differences in brain structure and function have been observed in people with BPD compared to those without the disorder. For example, imaging studies show abnormal activity in brain regions involved in emotion regulation, impulsivity, and self-identity.
While biology sets the stage, research indicates that environmental influences, especially during childhood, play a crucial role in the development of BPD.
Trauma and Abuse
There is a strong correlation between childhood trauma/abuse and developing BPD later in life. Studies estimate that anywhere from 30-90% of people with BPD report being abused or neglected as children.
Types of childhood trauma associated with BPD include:
- Emotional abuse
- Physical abuse
- Sexual abuse
- Emotional neglect
- Physical neglect
This early trauma interferes with the child’s ability to form a stable sense of self and manage emotions. The repeated lack of validation, nurturing, and cohesiveness leads the child to internalize a sense of worthlessness, mistrust others, and cope through maladaptive behaviors.
Prevalence of Childhood Abuse in BPD
|Percentage of BPD Patients Reporting Childhood Abuse
|Golier et al. (2003)
|Zanarini et al. (1997)
|Sansone et al. (2002)
In addition to overt abuse, an invalidating environment during childhood has also been implicated in BPD. An invalidating environment is one in which a child’s thoughts, emotions, and experiences are routinely dismissed or criticized by caregivers.
For example, a child who expresses feeling sad may be told to “get over it” or “stop being dramatic.” This repeatedly sends the message that the child’s inner experiences are wrong or undeserving of attention.
Growing up in an invalidating environment interferes with a child developing a secure sense of self and learning to understand, label, and regulate their emotions. They often feel like a part of themselves is “missing.”
Individuals with BPD often have insecure attachment styles. Attachment refers to the bond formed between a child and their primary caregiver (usually the mother) during infancy and early childhood.
A secure attachment provides the foundation for a child to develop emotionally. However, factors like abuse, neglect, or caregiver instability can disrupt healthy attachment.
Children who do not form secure attachments early in life tend to have difficulty trusting others and managing emotional distress as they get older. This puts them at higher risk for personality disorders like BPD.
Common Attachment Styles in BPD
- Anxious: Intense fear of rejection/abandonment, need for excessive reassurance
- Avoidant: Difficulty depending on others, lack of comfort seeking
- Disorganized: Confused/inconsistent behavior, unsure how to respond
Lack of Emotion Regulation Skills
Problems regulating emotions are a hallmark of BPD. Emotions tend to spiral out of control rapidly. But why?
Healthy emotion regulation skills are typically learned during childhood within the context of caregiver relationships. For example, a secure child expresses distress and receives soothing and comfort from their caregiver. This teaches them how to eventually self-soothe.
Without supportive caregivers to model and reinforce emotion regulation tactics, children struggle to manage intense emotions as adults.
In summary, research has demonstrated strong links between childhood trauma/abuse, insecure attachment, emotional invalidation, and lack of emotion regulation skills and the development of BPD later in life.
The most salient environmental risk factor appears to be abuse and neglect during childhood, which sets the stage for emotion dysregulation, unstable sense of self, and turbulent relationships.
However, not everyone with a history of childhood adversity develops BPD. There are likely complex interactions between biological vulnerabilities and environmental factors that ultimately determine risk.
With appropriate treatment and support, those with BPD can learn to manage their symptoms, heal from past trauma, improve relationships, and lead full, meaningful lives.