Genetic Causes of Borderline Personality Disorder

Are you wondering about the genetic causes of borderline personality disorder? You're not alone. Many people wonder why they or a loved one has borderline personality disorder (BPD). Unfortunately, there are no easy answers, but research is getting closer to understanding the causes of BPD.

Genetics or Environmental Causes

Studies of BPD in families show that first-degree relatives—meaning siblings, children, or parents—of people treated for BPD are ten times more likely to have been treated for BPD themselves than the relatives of people with schizophrenia or bipolar disorder.

However, while this suggests that BPD runs in families, studies of this type do not tell us exactly how much of BPD is due to genetics. That's because first-degree relatives share not just genes, but also environments in most situations. For example, siblings may be raised together by the same parents. This means that these studies may reflect, in part, any environmental causes of BPD as well.

Twin Studies Show Genetics Play a Large Role in BPD

A more direct, though still imperfect, way to study the influence of genes on BPD is to examine rates of BPD among identical versus fraternal twins. Identical twins have the exact same genetic makeup whereas fraternal twins only have similar genetic makeup, just like two regular siblings.

There have been a few twin studies of BPD, which have shown that 42% of variation in BPD is caused by genetics and 58% is caused by other factors, such as the environment.

This suggests that BPD is fairly strongly related to genetic causes. Yet, most likely an interaction of genes and environment leads to BPD in most people with the disorder.

What the Genetic Factor Means 

What does this mean for you? If you have BPD, it means that it is not your fault. You probably have a genetic predisposition to develop the disorder. Perhaps you have also experienced a few of the environmental events that seem to be linked to BPD in some cases, such as being abused as a child or losing a loved one.

You do not have BPD because you are “weak” or “can’t handle things.” There is a reason why you experience the symptoms you do.

If you have a first-degree relative with BPD, it means that you may have an increased chance of developing the disorder yourself. However, this by no means guarantees that you will develop BPD. In fact, chances are likely that you will not.

Why Treatment Is Essential

If you're concerned that you're showing signs of BPD, it's important to get treatment early. This will reduce any risk factors and help alleviate your symptoms. Speak to your doctor about your symptoms, testing for a proper diagnosis, and treatment options.

Borderline Personality Disorder Discussion Guide

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If you are a parent and you have BPD, you may be concerned about whether your kids will have BPD too. While it is a possibility, know that even though genes are important, they are not the sole cause of BPD.

There may be ways to ensure the environment you provide for your kids reduces their risk. Part of that is ensuring that you get treatment and that you stick with the treatment plan you and your doctor decide on. Psychotherapy may also be an option to help you learn effective parenting skills.