31st January 2024

Aetiology

Various factors contribute to the development of different types of personality disorder. 

Genetic factors

Studies have demonstrated the following genetic factors in the development of personality disorders:

• Borderline personality disorder has been linked to the presence of serotonin 1A and dopamine transporter gene variants. 
• Borderline personality disorder patients may have reduced nuclear expression of glucocorticoid receptors in blood mononuclear cells. 

Cluster A groups are said to have a link to schizophrenia; schizotypal personality disorder in the new ICD-11 is considered part of the “Schizophrenia or other primary psychotic disorders” and not a personality disorder and is called schizotypal disorder rather than being called a personality disorder.

Neurobiological factors

Various traits of personality disorders like impulsivity and emotional instability have been linked to dysfunction in neurotransmitters. It is believed that neurotransmitters such as Serotonin, Dopamine, and Glutamate/NMDA play a major role in the development of various traits of different personality disorders. Additionally, changes in the HPA axis have been linked to both borderline and antisocial personality disorders.

Psychological factors

Based on the psychodynamic theory, fixation at different stages can impede maturity/development with the individual stuck at this particular stage. Fixation at the oral stage could lead to dependent traits, and fixation at the anal phase can lead to having obsessive/compulsive traits. Also, attachment issues with parents can lead to development of traits of borderline personality disorder. 

Development and Adversities during Childhood

Physical and psychological traumas in early life are a major risk factor for developing personality disorders. Children who are victims of sexual abuse are at high risk of developing borderline personality disorder. Children with an ADHD diagnosis are at high risk of developing antisocial personality disorder.

References

• Joyce PR, Stephenson J, Kennedy M, Mulder RT, McHugh PC. The presence of both serotonin 1A receptor (HTR1A) and dopamine transporter (DAT1) gene variants increase the risk of borderline personality disorder. Frontiers in Genetics. 2014 Jan 7;4:313.
• López-Villatoro JM, MacDowell KS, Diaz-Marsá M, La Torre-Luque D, Prittwitz C, Galvez-Merlin A, Leza JC, Carrasco JL. Reduced glucocorticoid receptor expression in blood mononuclear cells of patients with borderline personality disorder. Frontiers in Psychiatry. 2022:1715.
• Gaebel W, Kerst A, Stricker J. Classification and diagnosis of schizophrenia or other primary psychotic disorders: changes from ICD-10 to ICD-11 and implementation in clinical practice. Psychiatria Danubina. 2020;32(3-4):320-4.
• Gurvits IG, Koenigsberg HW, Siever LJ. Neurotransmitter dysfunction in patients with borderline personality disorder. Psychiatric Clinics of North America. 2000 Mar 1;23(1):27-40.
• Moul C, Dobson-Stone C, Brennan J, Hawes D, Dadds M. An exploration of the serotonin system in antisocial boys with high levels of callous-unemotional traits. PloS one. 2013 Feb 15;8(2):e56619.
• Joyce PR, Stephenson J, Kennedy M, Mulder RT, McHugh PC. The presence of both serotonin 1A receptor (HTR1A) and dopamine transporter (DAT1) gene variants increase the risk of borderline personality disorder. Frontiers in Genetics. 2014 Jan 7;4:313.
• Friedel RO. Dopamine dysfunction in borderline personality disorder: a hypothesis. Neuropsychopharmacology. 2004 Jun;29(6):1029-39.
• Grosjean B, Tsai GE. NMDA neurotransmission as a critical mediator of borderline personality disorder. Journal of Psychiatry and Neuroscience. 2007 Mar 1;32(2):103-15.
• Aromäki AS, Lindman RE, Eriksson CP. Testosterone, aggressiveness, and antisocial personality. Aggressive Behavior: Official Journal of the International Society for Research on Aggression. 1999;25(2):113-23.
• Rausch J, Gäbel A, Nagy K, Kleindienst N, Herpertz SC, Bertsch K. Increased testosterone levels and cortisol awakening responses in patients with borderline personality disorder: gender and trait aggressiveness matter. Psychoneuroendocrinology. 2015 May 1;55:116-27.
• Strahl NR. Clinical study guide for the oral boards in psychiatry. American Psychiatric Pub; 2011.