What causes personality disorders?

Naomi Carr
Author: Naomi Carr Medical Reviewer: Morgan Blair Last updated:

Personality disorders are a group of mental health conditions that affect thoughts, behaviors, and relationships with others. People with personality disorders commonly experience emotional dysregulation, which can cause difficulties in various aspects of daily life and functioning. Personality disorders are often caused by a combination of genetic and environmental factors.

What are personality disorders?

Personality disorders impact thoughts, behaviors, emotions, and relationships. They often cause people to struggle with forming and maintaining interpersonal relationships, as well as regulating and expressing emotions. These challenges can lead to intense and overwhelming feelings, emotional outbursts, and distrust and/or instability in relationships [1].

Personality disorders tend to emerge and develop during childhood and adolescence, but aren’t often diagnosed until early adulthood. Symptoms can sometimes subside with age, although for some people, they may worsen [2].

Ten personality disorders are outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which are grouped into 3 clusters [3].

Cluster A

Cluster A personality disorders are characterized by odd or eccentric behaviors and thoughts. Cluster A types and their symptoms include:

Cluster B

Dramatic or volatile behaviors characterize cluster B personality disorders. Cluster B types and their symptoms include:

Cluster C

Anxious and fearful thoughts and behaviors characterize Cluster C personality disorders. Cluster C types and their symptoms include:

Causes of personality disorders

Personality disorders are often caused by a complex combination of genetic and environmental risk factors. These factors may vary depending on the type of personality disorder.


Currently, it is not clear exactly how genetics impact the development of personality disorders, although it is thought that some people have a genetic predisposition [4].

Recent research suggests that there are specific gene abnormalities associated with personality disorders that may be inherited. These genes are believed to impact the activity and production of certain neurotransmitters that influence emotion regulation [4][5].

Furthermore, it is also possible that people have specific personality traits that increase the likelihood of developing personality disorders. These traits may be inherited from parents, such as neuroticism, aggression, or a propensity to worry [6].

Childhood trauma

A great deal of research indicates a link between childhood exposure to trauma and the development of personality disorders. Much of this research focuses on borderline personality disorder, in which there is a high prevalence of childhood sexual abuse, particularly amongst those with severe symptoms [7][8].

Similarly, childhood sexual and physical abuse are found to be risk factors for antisocial and paranoid personality disorders. Childhood exposure to emotional abuse and neglect is a shared risk factor for all types of personality disorders. Typically, experiences of very severe childhood abuse correlate with the most severe symptoms in later life [8][9].

Childhood experiences greatly influence personality development and the understanding of social relationships. Exposure to trauma and abuse at a young age can lead to the development of maladaptive and unhealthy coping strategies, low self-worth, and interpersonal difficulties. As such, these experiences significantly impact the likelihood of developing a personality disorder [4].

However, it is important to note that not everyone who experiences childhood trauma and abuse will go on to develop a personality disorder, and not everyone with a personality disorder has experienced childhood trauma [1][6].


Various environmental factors can also influence the development of personality disorders. For example, the risk may be increased by growing up in a home with unstable or chaotic family dynamics or a lack of caregiver or parent support [1][10].

The risk may also be affected by other factors such as socioeconomic status, level of education, and cultural factors [5].


Although not always the case, gender differences are common in the development of personality disorders. For example, males are more likely to have antisocial personality disorder, while females are more likely to have borderline or histrionic personality disorders [5].

Can personality disorders be prevented?

Personality disorders often emerge in childhood, with certain behaviors or traits evident at a young age. However, diagnoses are not given until at least 18 years old. Some argue that a diagnosis at or after age 18, prevents the timely commencement of crucial preventative treatment. If signs are recognized early and interventions are implemented, there is a potential to prevent the development of severe symptoms [2].

As several factors commonly cause personality disorders. It is possible to alter or mitigate the risk of one or more of these factors, thereby slowing or preventing symptom development.

For example, many individuals with personality disorders experience childhood adversity. These experiences can lead to maladaptive thoughts and behaviors that underpin the symptoms of personality disorders. By implementing early intervention, these individuals can be provided with support that may enable them to learn positive coping strategies to process and manage distress [2][10].

Studies show that forming trusting therapeutic relationships is vital in treating personality disorders. Thus, it is likely helpful to give at-risk children and adolescents the opportunity to create these relationships prior to the development of a personality disorder. This may help to reduce the impact of their experiences and prevent the progression of severe symptoms [2][6][10].

  1. Mind. (2020). Personality Disorders. Mind. Retrieved from http://www.mind.org.uk/information-support/types-of-mental-health-problems/personality-disorders
  2. Chanen, A., Sharp, C., Hoffman, P., & Global Alliance for Prevention and Early Intervention for Borderline Personality Disorder. (2017). Prevention and Early Intervention for Borderline Personality Disorder: A Novel Public Health Priority. World Psychiatry: Official Journal of the World Psychiatric Association (WPA), 16(2), 215–216. Retrieved from https://doi.org/10.1002/wps.20429
  3. American Psychiatric Association. (2013, text revision 2022). Personality Disorders. In The Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.).APA. Retrieved from https://doi.org/10.1176/appi.books.9780890425787.x18_Personality_Disorders
  4. Ekselius, L. (2018). Personality Disorder: A Disease in Disguise. Upsala Journal of Medical Sciences, 123(4), 194–204. Retrieved from https://doi.org/10.1080/03009734.2018.1526235
  5. Fariba, K.A., Gupta, V., Kass, E. (2023). Personality Disorder. In: StatPearls [Internet].Treasure Island, FL: StatPearls Publishing. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK556058/
  6. American Psychological Association. (2010). What Causes Personality Disorders?APA. Retrieved from https://www.apa.org/topics/personality-disorders/causes
  7. de Aquino Ferreira, L.F., Queiroz Pereira, F.H., Neri Benevides, A.M.L., & Aguiar Melo, M.C. (2018). Borderline Personality Disorder and Sexual Abuse: A Systematic Review. Psychiatry Research, 262, 70–77. Retrieved from https://doi.org/10.1016/j.psychres.2018.01.043
  8. Yen, S., Shea, M.T., Battle, C.L., Johnson, D.M., Zlotnick, C., Dolan-Sewell, R., Skodol, A.E., Grilo, C.M., Gunderson, J.G., Sanislow, C.A., Zanarini, M.C., Bender, D.S., Rettew, J.B., & McGlashan, T.H. (2002). Traumatic Exposure and Posttraumatic Stress Disorder in Borderline, Schizotypal, Avoidant, and Obsessive-Compulsive Personality Disorders: Findings from the Collaborative Longitudinal Personality Disorders Study. The Journal of Nervous and Mental Disease, 190(8), 510–518. Retrieved from https://doi.org/10.1097/00005053-200208000-00003
  9. Bierer, L., Yehuda, R., Schmeidler, J., Mitropoulou, V., New, A., Silverman, J., & Siever, L. (2003). Abuse and Neglect in Childhood: Relationship to Personality Disorder Diagnoses. CNS Spectrums, 8(10), 737-754. Retrieved from https://doi.org/10.1017/S1092852900019118
  10. London: National Institute for Health and Care Excellence (NICE). (2013). Antisocial Personality Disorder: Prevention and Management. NICE Clinical Guidelines, No. 77. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK555205/
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Naomi Carr
Author Naomi Carr Writer

Naomi Carr is a writer with a background in English Literature from Oxford Brookes University.

Published: Jul 20th 2023, Last edited: Oct 23rd 2023

Morgan Blair
Medical Reviewer Morgan Blair MA, LPCC

Morgan Blair is a licensed therapist, writer and medical reviewer, holding a master’s degree in clinical mental health counseling from Northwestern University.

Content reviewed by a medical professional. Last reviewed: Jul 20th 2023