What Is the Science Behind Personality Disorders?

personality disorders, causes of personality disorders, what causes personality disorders

If you have ever wondered what is the science behind a personality disorder, you aren’t alone. Personality disorders are complex, difficult to treat and often hard to understand even for the people who are diagnosed with these mental health disorders. Personality disorders are something that the person who has them often doesn’t recognize.

Exploring the Science Behind Personality Disorders

Our personalities are an ingrained part of who we are, which is why it’s challenging to identify a personality disorder in yourself. This is one way these disorders are different from other mental health disorders. If you have a mental health disorder like anxiety, it likely causes you significant distress. You may realize your fears are unwarranted or irrational, but you can’t help it. In this way, you recognize your mental health disorder. This makes it easier to receive treatment because not only do you recognize it, but you understand the symptoms and you can explain them to a mental health care provider.

With a personality disorder, an impacted person often doesn’t see themselves as a problem. They see others around them as the problem or their environment as a problem. Personality disorders can cause significant distress, not for the people who struggle with them, but the people around them. Someone with a personality disorder may not have any idea the effects it has on the people around them.

This sense of unawareness is one of the reasons when a health care provider is diagnosing a personality disorder, they will often ask for permission to speak with the loved ones of the individual with the suspected disorder. Speaking with family members or a spouse can give a much clearer idea of whether or not someone has a personality disorder.

This is just one aspect of understanding the science behind personality disorders. There’s more to them than that sense of unawareness and lack of recognition.

What Are Personality Disorders?

Before exploring the question of “what is the science behind a personality disorder” in more detail, it’s useful to have a general understanding of what these disorders are.

Personality disorders are deeply ingrained ways of thinking and behavior that are inflexible and lead to problems in relationships. While not everyone with a personality disorder has distress because of it, many do.

There are 10 formally recognized personality disorders that are grouped into three clusters. As is the case with certain other mental disorders, personality disorders exist on a spectrum of severity. So, it’s possible to have a mild personality disorder or it could be characterized as severe.

The following are the groupings for personality disorders also known as clusters.

  • Cluster A personality disorders are defined by behaviors that seem odd, abnormal or outside of societal norms. Cluster A personality disorders including paranoid, schizoid and schizotypal personalities.
  • Cluster B personality disorders are characterized by dramatic, unpredictable or erratic behaviors and patterns of behavior. Disorders that fall into Cluster B include narcissistic personality disorder, borderline personality disorder and histrionic personality disorder.
  • Cluster C disorders are marked by fearful or anxious thoughts and behaviors. Specific disorders in this category are avoidant personality disorder, dependent, and obsessive-compulsive personality disorders.

When Do the Signs of a Personality Disorder First Appear?

If you are curious to answer “what is the science behind a personality disorder,” you may wonder when the symptoms first appear. For most people, the signs and symptoms of a personality disorder will first appear in late adolescence or perhaps early adulthood.

It’s common for someone with a personality disorder to experience symptoms from another disorder as well. For example, someone with borderline personality disorder might also showcase at least one or maybe a few signs of histrionic personality disorder.

What Causes Personality Disorders?

The primary thing to consider when answering “what is the science behind a personality disorder” is what causes them. Researchers aren’t exactly sure, but currently, the theory is that personality disorders are caused by a combination of factors including genetics and childhood trauma or abuse.

what causes personality disorders, why do people get personality disorderes, why do people develop personality disorders
Image Source: Pixabay


Genetic factors are one of the primary reasons researchers believe some people have personality disorders while others don’t. There are certain genes being currently identified that might provide more understanding into personality disorders. There are also believed to be links between aggression, anxiety and fear with genetics.

Childhood Trauma

Researchers are starting to see the significant links in childhood trauma and personality disorders. For example, one specific study called the Collaborative Longitudinal Personality Disorders Study found relevant information linking childhood experiences with the later development of personality disorders.

The study found a link between the number of traumas experienced in childhood as well as the type of traumas and the later development of personality disorders.

One example was a high rate of childhood sexual trauma that seemed to demonstrate a link to borderline personality disorders.

Verbal abuse in childhood may play a role in developing personality disorders also. For example, there was a study looking at 793 mothers and children. Researchers asked questions to the mothers and children about verbal abuse. Children who experienced reported verbal abuse were three times more likely to have narcissistic, borderline, obsessive-compulsive or paranoid personality disorders when they reached adulthood.

Personality Disorders and the Brain

what causes personality disorders, causes of a personality disorder, reasons for a personality disorder, science of personality disorder
Image Source; Pixabay

Researchers in Canada found possible links between the brain and personality disorders. In particular, their research which was done by a team at the University of Toronto found potential links to the brain regions that process anger and sadness and the development of borderline personality disorder.

Researchers found that the areas of the brain that help control negative emotions were underactive in people with borderline personality disorder.

Based on this particular information, researchers are now looking at ways to use brain imaging as a way to definitively diagnose personality disorders.

Personality Disorder Risk Factors

Some of the specific risk factors that may play a role in developing a personality disorder are:

  • A family history of personality disorders as well as other mental illnesses
  • A chaotic, unstable or abusive childhood
  • Having a childhood conduct disorder
  • Differences in the structure and chemical makeup of the brain

Personality disorders remain a mystery in many ways, but more and more research is being done on what causes them, helping provide answers to “what is the science behind personality disorders.” Personality disorders can also be treated through a combination of therapy and medication and many people can go into remission from the symptoms of a personality disorder with appropriate treatment.


Majad, Sanaz Dr. “What Are Personality Disorders?” Scientific American. February 22, 2017. Accessed January 26, 2019.

Mayo Clinic Staff. “Personality Disorders.” Mayo Clinic. Accessed January 26, 2019.

Robitz, Rachel M.D. “What Are Personality Disorders.” American Psychiatric Association. November 2018. Accessed January 26, 2019.

American Psychological Association. “What Causes Personality Disorders?” Accessed January 26, 2019.

Leave a Reply

Your email address will not be published. Required fields are marked *