Understanding the Causes of Borderline Personality Disorder




Borderline personality disorder (otherwise known as BPD) is a complex mental health condition characterized by intense emotional instability and impulsive behaviors that impact daily functioning and relationships. Individuals who have this disorder will experience frequent episodes of overwhelming anger, anxiety, and depression that can last anywhere from a few hours to a few days.
If you or someone you know has BPD, it is essential to understand the condition’s origin, as this can help guide its effective management and treatment, offering hope and a better quality of life to those affected.

What Causes BPD?
Experts believe a variety of genetic, environmental, and neurobiological factors cause BPD [1]. That being said, it’s essential to note that every case of BPD is unique. While some individuals may exhibit all the risk factors for BPD without developing symptoms, others may experience only one and still face significant challenges. This variability highlights the unique nature of each case and underscores the importance of a personalized approach to diagnosis and treatment.
Genetic Causes of BPD
Genetics plays a significant role in the development of BPD. A family history of BPD or related mental health conditions increases the likelihood of having the disorder. To be more specific, studies have shown that BPD has a heritability rate of roughly 46%. Additionally, specific temperamental characteristics, such as emotional sensitivity and impulsivity, may also be inherited from family members [2].
Research into this topic has identified several genetic markers that are closely related to an increased risk of developing BPD. Two genes in particular, namely DPYD and PKP4, are linked to a higher likelihood of the condition. The same genes are also associated with an increased risk of other mental health conditions, such as schizophrenia and bipolar disorder [3].
Environmental Causes of BPD
Environmental factors also play a significant role in the development of Borderline Personality Disorder. This means that an individual’s upbringing, past experiences, and current situation all have an impact on their overall mental state.
Childhood trauma, such as emotional, physical, or sexual abuse, has been strongly associated with BPD. Experts believe that frequent experiences of criticism, rejection, and invalidation during formative years can lead to emotional instability, thus triggering the condition. Physical abuse also causes feelings of fear, helplessness, and instability, which are closely linked to BPD [4].
Parenting Styles
The parenting style with which a child is raised is pivotal to their likelihood of developing BPD. Suppose a parent is harsh, dismissive, and emotionally unavailable. In that case, the child is more likely to develop emotional instability themselves, which will cause them to find difficulty in managing their feelings and thoughts. Moreover, an inconsistent parenting style can lead to feelings of insecurity and a fear of abandonment [5].
Research shows that children who struggle with these emotions throughout their formative years (between the ages of 0 and 8) are more likely to develop BPD. With that being said, trauma that occurs later on in life can also lead to the condition, but it is just less likely.
Peer Relationships
Studies show that individuals who experience negative peer interactions during childhood and adolescence, such as bullying or social rejection, are more likely to develop BPD. This is a result of low self-esteem caused by years of feeling rejected by their peers [4].
A lack of supportive relationships can also exacerbate the challenges that an individual with BPD faces. Feelings of loneliness and isolation are heavily linked to the condition, as well as several additional mental health disorders, such as depression and chronic anxiety. This is why it is so important for younger children and teenagers to have access to a strong support system.
Life Events
Finally, stressful life events can trigger BPD in individuals of all ages. This includes prolonged exposure to stressful situations, such as living in an unstable environment or experiencing abuse of any kind, and the loss of a loved one or the end of a significant relationship, all of which can trigger or exacerbate symptoms of BPD [4].
Neurobiological Causes of BPD
Brain imaging studies reveal that neurobiological differences, such as changes in brain structure, also contribute to the development of Borderline Personality Disorder [4]. This can include hyperactivity in the amygdala, reduced activity in the prefrontal cortex, a smaller hippocampus, and imbalances in neurotransmitters.
Brain Structure and Function
The amygdala, the part of the brain responsible for processing emotions, tends to become hyperactive in individuals with BPD, resulting in a heightened emotional response. Additionally, the prefrontal cortex, which is responsible for regulating impulses and emotions, is less active in patients with BPD. This leads to impulsivity and emotional instability. Finally, the hippocampus, which is responsible for managing memory and stress regulation, appears to have a reduced volume in individuals with the disorder.
Neurotransmitters
Individuals with BPD show signs of altered serotonin levels. This is a neurotransmitter linked to mood regulation. Low serotonin levels lead to heightened emotions, including depression, aggression, and challenges in controlling destructive urges. Dopamine dysregulation, affecting an individual’s motivation, is also closely linked to the development of BPD [4].
Emotional Dysregulation and BPD
There is a very close link between emotional dysregulation and BPD. Essentially, emotional dysregulation refers to an individual’s inability to manage and respond to their emotions in a typical or socially accepted manner. Emotional dysregulation can create a cycle that reinforces a person’s symptoms. Some features of emotional dysregulation include:
- Intense emotions: Emotional dysregulation means that the individual will experience their feelings more intensely than others. Often, this becomes overwhelming and stressful, which heightens their emotions even further and creates a vicious cycle.
- Severe and rapid mood swings: Emotional dysregulation causes the person’s emotional state to shift quickly and unpredictably. Again, this is stressful for the individual, as they often can’t pinpoint why their emotions have moved in the first place.
- Difficulty regulating emotions: The individual will also struggle to control their emotional reactions. This can lead to prolonged bouts of emotional pain, as it can sometimes take days for their emotional state to return to baseline [1].
Sociocultural Influences on BPD
Individuals with borderline personality disorder have emotional responses that are typically intense, rapid, and difficult to control, mainly when triggered by interpersonal conflict or perceived rejection. However, these heightened responses are not solely driven by internal psychological or neurobiological factors; they are also shaped by external influences [4].
Sociocultural dynamics, such as gender expectations, stigma surrounding mental illness, and cultural norms around emotional expression, can significantly affect how individuals with BPD experience their condition and how others respond to their behaviors.
Cultural Representations
Cultural norms and expectations surrounding emotions and relationships vary widely, shaping how individuals with BPD are understood and treated within different societies. For example, expressions of intense emotions like depression or anger may be met with empathy and acceptance in some cultures, while in others, such behaviors may be misunderstood or stigmatized.
Additionally, gender roles often dictate what is considered ‘appropriate’ emotional expression for men and women, potentially adding another layer of complexity for people with BPD who may struggle to conform to these societal expectations. Understanding these cultural nuances is essential for fostering compassion and creating supportive environments for those living with BPD [6].
Effective Treatment for BPD
For individuals diagnosed with borderline personality disorder (BPD), identifying contributing factors, such as trauma, neurobiological differences, or environmental stressors, is key to developing a personalized treatment plan. Tailoring care to an individual’s unique needs enhances the effectiveness of interventions and promotes long-term stability. Standard treatment options include:
- Dialectical Behavior Therapy (DBT): A structured form of therapy that teaches emotional regulation, distress tolerance, mindfulness, and interpersonal effectiveness. It is especially effective in reducing self-harming behaviors and improving emotional control.
- Trauma-Focused Cognitive Behavioral Therapy (TF-CBT): Aims to help individuals process and reframe traumatic experiences, making it particularly suitable for those with a history of abuse or neglect.
- Schema Therapy: Focuses on identifying and transforming deeply ingrained negative beliefs and behavioral patterns that stem from early life experiences.
- Mentalization-Based Treatment (MBT): Helps individuals understand their own and others’ thoughts and feelings, improving self-awareness and social functioning.
- Medications: Although there are no medications specifically approved for BPD, certain psychiatric drugs, such as mood stabilizers, antidepressants, or antipsychotics, may be prescribed to target co-occurring symptoms like anxiety, depression, or impulsivity.
- Support Systems and Lifestyle Adjustments: Participation in peer support groups, establishing routines, practicing self-care, and maintaining a strong therapeutic alliance are critical components of ongoing recovery.
Integrating these approaches within a comprehensive, individualized treatment plan can significantly improve emotional stability, interpersonal relationships, and overall well-being.
Building Awareness and Reducing Stigma
Understanding the early signs of borderline personality disorder (BPD) is essential for promoting mental well-being and preventing symptom escalation. Individuals with a family history of BPD may be at a higher risk of developing the condition. By recognizing early warning signs, such as intense emotional reactions, difficulty managing relationships, or impulsive behavior, loved ones and healthcare providers can take proactive steps to intervene and provide support. Preventive strategies may include fostering emotional resilience, encouraging healthy coping mechanisms, and creating stable and supportive environments.
Reducing the stigma surrounding BPD is another critical component of early intervention. Misunderstandings about the condition often lead to harmful stereotypes or misdiagnoses, with individuals unfairly labeled as “difficult” or “manipulative.” Educating the public and healthcare professionals about the true nature of BPD promotes empathy and improves diagnostic accuracy, ensuring that individuals receive appropriate and compassionate care.
Encouraging support and recognition also play a vital role in improving outcomes. Despite being relatively common, many cases of BPD remain undiagnosed. Raising awareness among families, educators, and healthcare providers helps with early identification and connects individuals with the necessary resources. With a better understanding of symptoms and behaviors, support networks can respond more effectively, offering validation, guidance, and access to professional care.
Why Understanding the Roots of BPD Matters
Borderline personality disorder is a complex mental health condition influenced by a combination of genetic, environmental, and neurobiological factors. Its various potential causes, such as genetic predisposition, childhood trauma, and brain structure abnormalities, highlight the need for tailored treatment approaches that address each individual’s unique experiences and needs.
Raising awareness about BPD’s origins not only reduces stigma but also empowers individuals and their support networks with knowledge that can foster empathy and proactive care. With early intervention and personalized treatment strategies like DBT or CBT, those affected by BPD can achieve emotional stability and lead more fulfilling lives.
- National Institute of Mental Health. (n.d.). Borderline personality disorder. U.S. Department of Health and Human Services, National Institutes of Health. https://www.nimh.nih.gov/health/publications/borderline-personality-disorder
- Ansari, D., Lakkimsetti, M., Olaleye, K. T., Bhullar, J. V. K., Shah, R. Z., et al. (n.d.). Genetic influences on outcomes of psychotherapy in borderline personality disorder: A narrative review of implications for personalized treatment. Cureus. https://doi.org/10.7759/cureus.51832
- Witt, S. H., Streit, F., Jungkunz, M., Frank, J., Awasthi, S., et al. (n.d.). Genome-wide association study of borderline personality disorder reveals genetic overlap with bipolar disorder, major depression, and schizophrenia. Molecular Psychiatry. https://doi.org/10.1038/s41380-020-01002-4
- Bozzatello, P., Garbarini, C., Rocca, P., & Bellino, S. (2021). Borderline Personality Disorder: Risk Factors and Early Detection. Diagnostics, 11(11), 2142. https://www.mdpi.com/2075-4418/11/11/2142.
- Trupe, R. D., Macfie, J., Skadberg, R. M., Kurdziel, G., et al. (2018). Patterns of emotional availability between mothers and young children: Associations with risk factors for borderline personality disorder. Development and Psychopathology, 30(3), 941–955. https://doi.org/10.1017/S0954579417001676
- Munson, K. A., Janney, C. A., Goodwin, K., Nagalla, M., et al. (2022). Cultural representations of borderline personality disorder. The Behavior Therapist, 45(3), 119–126. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8990760
The Clinical Affairs Team is a dedicated group of medical professionals with diverse and extensive clinical experience who actively contribute to the development of our content, products, and services. They meticulously evaluate and review all medical content before publication to ensure it is medically accurate and aligned with current discussions and research developments in mental health. Please visit our Editorial Policy for more information.
MentalHealth.com is a health technology company guiding people towards self-understanding and connection. The platform provides reliable resources, accessible services, and nurturing communities. Its purpose is to educate, support, and empower people in their pursuit of well-being.
Annie Gurton holds a Master’s in Psychotherapy from Nottingham Trent University. She primarily writes about therapy, attachment, and personality disorders.
Dr. Brittany Ferri, PhD, is a medical reviewer and subject matter expert in behavioral health, pediatrics, and telehealth.
The Clinical Affairs Team is a dedicated group of medical professionals with diverse and extensive clinical experience who actively contribute to the development of our content, products, and services. They meticulously evaluate and review all medical content before publication to ensure it is medically accurate and aligned with current discussions and research developments in mental health. Please visit our Editorial Policy for more information.
MentalHealth.com is a health technology company guiding people towards self-understanding and connection. The platform provides reliable resources, accessible services, and nurturing communities. Its purpose is to educate, support, and empower people in their pursuit of well-being.