The debate of nature versus nurture has been prevalent throughout psychological research since the concept of heritability was first understood. When you first try to understand BPD, one of the questions you’ll likely be asking your doctor, or google, is why? What has caused the personality disorder to manifest?
The answer you’re given is usually a combination of two; your genes have determined that you will have BPD since you were born, or there have been factors in your life and childhood that caused or allowed the disorder to develop as you grew. Even with my minimal scientific background, I don’t entirely understand what this means, and in particular what this means for me. Was I born with BPD?
Psychologists have tried to answer these questions by studying families where a family member has BPD, to see whether members of the same family, with shared genes, are likely to share the disorder. If more than one member of the same family was diagnosed with BPD or showed BPD like traits, this could suggest a degree of heritability. However, members of the same family tend to grow up in a very similar environment, meaning that the BPD traits could have been recreated by a similar familial environment rather than inherited.
Neuroscientists and neuropsychologists have also attempted to find out to what extent genes and biology play a role in the development of BPD. Impulsive aggression is a symptom of many cluster B personality disorders, including BPD. It manifests in people with BPD through self harm, and impulsive and aggressive acts against yourself. Scientists have found that there is a relationship between the serotonergic system in the brain, and impulsive aggression. Essentially, many people with cluster B personality disorders have low serotonin levels in the brain. A chemical difference like this could predispose someone to experience mental illness and BPD later in life. This discovery was also important because it has lead to the use of medications to help manage the symptoms of BPD such as selective serotonin re-uptake inhibitors. you can read more about my experience with this medication here.
Neuroimaging has shown that the brain of someone with BPD is significantly different to the brain of a neurotypical healthy person. These differences could be produced by either the genetic or environmental causes of BPD, because our brain has the ability to change based on how we use it. If we have learned to use our brain ‘the BPD way’ then through plasticity, aspects of our brain change in response to the way we use it. Through researching for this post, I have discovered that there is too much to talk about when comparing the brain images of healthy and borderline subjects here, so I will devote a new post to this topic in the future.
Although I feel much better informed about the known biological and genetic causes of borderline personality disorder, I am finding the information hard to relate to on a personal level. I have no family members who have been diagnosed with BPD or even experience the characteristic symptoms or behaviours on a lesser level. This makes me question whether I inherited the disorder from my parents at all. Additionally, I have found serotonin based medication fairly unhelpful. Although this doesn’t mean I don’t have low levels of serotonin, as there are many different medications available and I have only tried one of them.
It is well known among the psychiatric community that many people who are diagnosed with BPD share the same or similar negative childhood experiences. These experiences are so incredibly prevalent, it is unlikely to be coincidental.
The ‘nurture’ argument states that people will develop BPD because negative experiences have taught the child to develop maladaptive behaviours as coping skills, which are used in place of emotion regulation because the child has not been provided with the opportunity to learn this skill.
I am hesitant to create a list of childhood environments and experiences that contribute to the development of BPD, because I know how varied and individual the experiences leading to BPD are. Mind, a mental illness charity provides a simple list of reasons why a child may not gain enough experience of healthy emotions and relationships. Living with an unreliable parent, for example a parent with an addiction problem, could cause a child to develop the belief that they are unimportant, and that everyone will eventually abandon them. When this belief grows into adulthood, it could manifest in symptoms of BPD such as an extreme fear of abandonment or self harm.
Personally, I find the environmental causes of BPD easier to understand, the path from cause to result is easy to visualise and fairly simple to follow. However, I am not able to pin point an area in my childhood where I may have been made more susceptible to develop BPD. Like many children I was bullied in primary school, and my parents went through a divorce. However, the bullying was dealt with and ended when I moved schools, and the divorce was nothing special and finished while I was still young. I was not neglected or abused as a child. I had a reasonably happy childhood, and wouldn’t change any part of it. However, I do have BPD. I can understand how if I was genetically predisposed to be sensitive to the triggers of BPD, unhealthy lessons about emotions and relationships that I was exposed to in my childhood could have accumulated to affect my emotional development and behaviour in adult life.
If you feel a particular way about whether your BPD was more influenced by genetics or your environment I would be really interested to know, please get in touch!
Thank you for reading,
Borderline Bella xxx