• Clinical science

Personality disorders


Personality disorders (PD) are conditions and deeply rooted behavioral traits that differ significantly from the expected and accepted norms of the individual's culture. Consequently, regional and cultural characteristics should always be taken into account when considering diagnosing a patient with a personality disorder. Personality disorders are characterized by maladaptive behavioral traits that usually arise during adolescence and are difficult to influence or treat. A key feature of personality disorders is that they must cause impairment in social and/or occupational functioning. Patients with personality disorders typically have ego-syntonic symptoms (they lack insight as to their symptoms, considering them to be normal and not a problem). Personality disorders increase the risk of developing other mental disorders, especially in times of stress.


  • Definition: pervasive, inflexible, and maladaptive personality patterns that lead to significant distress or impairment, and are stable over time
  • Etiology: multifactorial, combination of genetic (e.g., personality disorders in parents) and psychosocial factors (e.g., child neglect, abuse) influencing incidence
  • Epidemiology
    • Age of onset: late childhood or adolescence
    • Antisocial and narcissistic PDs are more common in males; histrionic and borderline PDs are more common in females
  • Classification: DSM-5 classifies personality disorders in three clusters based on similar characteristics:
Cluster Prevalence Family history association Characteristic behavior Personality disorder
Cluster A
  • ∼ 5% (increases if there is a positive family history of schizophrenia)
  • Psychotic disorders
  • Odd
  • Eccentric
Cluster B
  • ∼ 2%
  • Mood disorders
  • Dramatic
  • Emotional
  • Erratic
Cluster C
  • ∼ 5%
  • Fearful
  • Avoidant
  • Anxious
  • Clinical features: ego-syntonic symptoms (they lack insight as to their symptoms, considering them to be normal and not a problem)
  • Diagnostic criteria
    • Thinking and behaviors that significantly deviate from cultural expectations; at least ≥ 2 patterns are present
      1. Cognition (e.g., perceives events, others, or self in an inappropriate way)
      2. Affectivity
      3. Interpersonal functioning
      4. Impulse control
    • Begins in early adulthood and stable over time
    • Leads to significant distress and impaired functioning in important areas of life (e.g., socially, occupational)
    • Not caused by another mental disorder, substance abuse, or another medical condition
  • Treatment

Personality disorders increase the risk of developing mental disorders, especially during times of stress!


Cluster A


Cluster B

  • Antisocial personality disorder
    • A history of a conduct disorder
    • ≥ 3 of the following 7 criteria after the age of 15 years:
      • Repeatedly engaging activities that are grounds for arrest
      • Deceitfulness
      • Impulsivity/failure to plan ahead
      • A history of repeated aggression
      • Reckless disregard for one's own safety or the safety of others
      • A failure to fulfill work-related or financial obligations
      • A lack of remorse or emotional indifference to the plight of others
  • Borderline personality disorder
    • Unstable personal relationships and fear of abandonment
    • Lack of impulse control
    • Self-harm
    • Often exhibits splitting (defense mechanism in which relationships are categorically good or bad)
  • Histrionic personality disorder
    • Attention-seeking, excessively emotional behavior
    • Often exhibits inappropriately sexually provocative and/or seductive behavior
    • Draws attention to self by way of physical appearance
    • Overestimates the degree of intimacy in relationships
    • Becomes uncomfortable when not the center of attention
  • Narcissistic personality disorder
    • Attention seeking, grandiosity, and need for admiration
    • Difficulty dealing with criticism
    • Lack of empathy


Cluster C

Unlike schizoid personalities, avoidant personality disorder patients do wish to establish social relationships but find it difficult due to their extreme shyness and social anxiety!

  • Dependent personality disorder
    • Difficulty making everyday decisions often requiring others to assume responsibility
    • Difficulty initiating projects (e.g., applying for jobs) due to lack of self-confidence
    • Feelings of helplessness when alone, and urgently seeking new relationships once one fails

Dependent personalities are both afraid of being abandoned and afraid to abandon their partner and are associated with an increased risk of suicide!

Features of obsessive-compulsive personality disorder often occur at the expense of occupational success (e.g., missing deadlines), social relationships (e.g., excluding social activities to complete tasks), and pleasurable activities (e.g., not taking vacation)!


  • 1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM–5). https://www.psychiatry.org/psychiatrists/practice/dsm. Accessed May 26, 2017.
  • 2. Skodol A. Overview of Personality Disorders. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/overview-of-personality-disorders. Last updated December 1, 2017. Accessed May 24, 2018.
  • 3. Ganti L, Kaufman MS, Blitzstein SM. First Aid for the Psychiatry Clerkship. McGraw Hill Professional; 2016.
  • Kaplan Medical. USMLE Step 2 CK Lecture Notes 2017: Psychiatry, Epidemiology, Ethics, Patient Safety. New York, NY: Simon and Schuster; 2016.
last updated 01/15/2019
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