What Causes Borderline Personality Disorder?

What Causes Borderline Personality Disorder?

While we have a lot of research concerning mental health, there are still many questions about the causes behind specific conditions. For some time now, researchers have been asking what causes borderline personality disorder (BPD) and have only come to so many answers.

Still, we do know of a few factors that could lead to the condition. Furthermore, it’s believed that BPD is caused by multiple elements rather than a single factor.

Throughout this article, we’re going to take a deeper look into BPD and what may cause it. At the end, we invite you to ask further questions.

What is Borderline Personality Disorder?

Borderline personality disorder (BPD) is a mental health condition that is pronounced by the following: ¹

  • Behavior
  • Mood swings
  • Self-image

More specifically, someone with BPD is likely to experience intense mood swings while also facing uncertainty in how they view themselves and their place in this world. Due to this, their interests, values, and behavior can show rapid changes.

Those who struggle with the condition are likely to view life through extremes – usually all good or all bad. For example, if you’re good friends with someone who has BPD, they may unexpectedly view you as an enemy the next day.

Such intense emotions often lead to instability in a person’s ability to complete day-to-day tasks and develop relationships. Not to mention, people with BPD are likely to experience symptoms of other mental illnesses, such as anxiety and depression.

BPD Symptoms

Common symptoms of borderline personality disorder include:

  • Abandoment issues (both real and imagined)
  • Anger issues (inappropriate, intense anger)
  • Difficulties with self-image (distorted or unstable)
  • Dissociation from other people and reality
  • Engaging in impulsive behaviors (i.e. spending sprees, unsafe sex, substance abuse, etc.)
  • Feelings of emptiness
  • Lack of trust for other people (irrational fears)
  • Sequences of unstable and intense relationships

It’s worth noting that not everyone with BPD will experience all these symptoms. Furthermore, some symptoms may be a product of another mental illness. For example, if you find yourself engaging in risky behavior, but only during periods of elevated mood, you’re likely struggling with a mood disorder. ²

BPD Symptoms

What Causes Borderline Personality Disorder?

While researchers still aren’t sure exactly what causes BPD, there’s evidence to suggest it’s a combination of multiple factors. ³ Still, it’s important to note that there’s only so much research into BPD causes. With that said, we may only have a small understanding of something much larger.

As of this time, scientists agree the following can lead to BPD:

Brain Chemistry

Within our brains are neurotransmitters that act as “messenger chemicals” to link signals between brain cells. ⁴ While there’s only so much evidence to suggest, many scientists believe those who struggle with BPD have something wrong with their neurotransmitters. More specifically, serotonin. ⁵

In one review study, it was found that there is a relationship between impulsive aggression and serotonin dysfunction. Furthermore, the study found that emotional difficulties may also be caused by imbalances in cholinergic, noradrenergic, and GABAminergic neurotransmissions – though, to a lesser degree. ⁶

Brain Development

Beyond neurotransmissions, researchers have used MRI scans to observe other areas of the brain that may cause BPD. In one study, it was discovered that people with BPD had irregularities in the following areas of the brain: ⁷

  • Amygdala – is a key player in emotional regulation, especially “negative” emotions, such as agression, anxiety, and fear. ⁸
  • Hippocampus – is important in regulated behaviors and self-control. ⁹
  • Orbitofrontal Cortex – is used when making plans and decisions. ¹⁰

Since these areas of the brain are most affected during your upbringing, certain childhood developments may lead to BPD.

Environmental Factors

In order for the brain to change in such an intense manner, it’s likely environmental factors play a role. For people with BPD, these may include: ¹¹

  • Exhibiting fear or distress during childhood
  • Growing up with a amily member who struggles with a mental illness, such as bipolar disorder
  • Neglection from one or both parents
  • Victimization of emotional, physical, or sexual abuse

However, there are a few other factors of childhood that may lead to BPD. These include: ¹²

  • Conducting yourself so other people are adults and you’re not
  • Expecting people to bully you (even strangers)
  • Idealising other people
  • Seeing parents in other people
  • Unresolved fear, distress, and anger


One of the most significant causes of BPD is genetics. If you have a close family member (parent, sibling, cousin, aunt, etc.) who’s been diagnosed with BPD, you’re more likely to struggle with it.

One study found that an identical twin with BPD gave their other identical twin a 2-in-3 chance of having the condition. ¹³

However, genetics cannot be a determining factor for BPD. With that, scientists view it as a cautionary sign that someone may develop the condition. Especially if they’re vulnerable to other causes of BPD.

Genetics of BPD

Final Word

If you believe you’ve been affected by the causes of borderline personality disorder, you may want to seek out a mental health professional. Unfortunately, BPD is such a complex condition that these causes alone won’t determine a diagnosis.

BPD is a difficult disorder, but it can be managed with talk therapy and medication. You may also find that incorporating certain vitamins and supplements into your diet can help to ease symptoms.

Your Questions

Still have questions concerning what causes borderline personality disorder?

We invite you to ask them in the comments section below. If you have any further knowledge to share – whether personal or professional – we’d also love to hear from you.

Reference Sources

¹ National Institute of Mental Health (NIMH): Borderline Personality Disorder

² Journal of affective disorders (PubMed): Increased energy/activity, not mood changes, is the core feature of mania

³ The Department of Health (Australian Government): What causes personality disorders?

⁴ StatPearls: Physiology, Neurotransmitters

⁵ Acta neuropsychiatrica: Serotonin, personality and borderline personality disorder

⁶ Neuropsychopharmacology: Dopamine Dysfunction in Borderline Personality Disorder

⁷ Journal of Psychiatry & Neuroscience: Neuroimaging and genetics of borderline personality disorder

⁸ Neuroscience Online: Limbic System: Amygdala

⁹ StatPearls: Neuroanatomy, Hippocampus

¹⁰ Brain and cognition: The functions of the orbitofrontal cortex

¹¹ HHS Public Access: Structure of Genetic and Environmental Risk Facts for Symtpoms of DSM-IV Borderline Personality Disorder

¹² HHS Public Access: Borderline Personality Features in Childhood

¹³ Molecular Psychiatry: Familial risk and heritability of diagnosed borderline personality disorder

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