Introduction to Personality Disorders

Personality disorders are enduring patterns of behaviours and inner experiences that deviates significantly from the expectations of an individual's culture. These patterns begin in adolescence or early adulthood, are pervasive and inflexible, usually remain stable over time. A core feature of personality disorders is that they also must lead to distress or impairment. The DSM-5's conceptualization of personality disorders is grouped into three clusters based on descriptive similarities:

  1. Cluster A includes paranoid, schizoid, and schizotypal personality disorders; these individuals can appear odd or eccentric.
  2. Cluster B includes antisocial, borderline, histrionic, and narcissistic personality disorders; these individuals can appear dramatic, emotional, or erratic.
  3. Cluster C includes avoidant, dependent, and obsessive-compulsive personality disorders; these individuals often appear anxious or fearful.

Prevalence estimates for any personality disorder is 9.1%, with Cluster A personality disorders at 5.7%, Cluster B at 1.5%, and Cluster C at 6%. The prevalence for any personality disorder ranges from 9%-15%.[1][2]


The prognosis of a personality disorder depends on the specific personality disorder. For example, antisocial and borderline personality disorder tends to improve or self-extinguish with age. Other personality disorders, like obsessive-compulsive personality disorder and schizotypal personality disorder are less likely to remit over time.

  • Personality disorders are highly co-morbid with other personality disorders, and there is high overlap between the different clusters.

Personality traits are an enduring, repetitive pattern of perceiving, relating to, and thinking about the environment and oneself. Personality traits are not disorders.

The dimensional model of personality disorders is a new proposed model and approach to personality disorders. In contrast to the current model, this approach proposes that personality disorders are maladaptive variants of personality traits that merge subtlety with normal behaviour and other personality traits.[3] The integration, clinical utility, and relationship of the dimensional approach with the current personality disorder diagnostic categories remain under research.

A Word to the Wise...

The current DSM-5 approach of diagnosing and clustering personality disorders in groups has serious limitations, both from a clinical and research perspective. The DSM-5's diagnostic approach is based on a categorical (or “binary”) approach that treats personality disorders as a qualitatively distinct clinical syndrome (i.e. - “either you have a personality disorder or you don't”). This approach has been rightfully criticized, and alternative models to personality disorders have been suggested, including a dimensional approach.[4][5]

Personality Disorders Under Age 18

For a personality disorder to be diagnosed in an individual younger than 18 years, the features must have been present for at least 1 year. The one exception to this is antisocial personality disorder, which cannot be diagnosed in individuals younger than 18 years old. These individuals would instead likely meet criteria for a diagnosis of conduct disorder.

The diagnosis for a general personality disorder is as follows (refer to a specific personality disorder for more specific criteria):

Criterion A

An enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual's culture. This pattern is manifested in 2 (or more) of the following areas:

  1. Cognition (i.e - ways of perceiving and interpreting self, other people, and events)
  2. Affectivity (i.e. - the range, intensity, lability, and appropriateness of emotional response)
  3. Interpersonal functioning
  4. Impulse control
Criterion B


Criterion C


Criterion D


Criterion E

The enduring pattern is not better explained as a manifestation or consequence of another mental disorder.

Criterion F

The enduring pattern is not attributable to the physiological effects of a substance (e.g. - a drug of abuse, a medication) or another medical condition (e.g. - head trauma).

  • Whenever diagnosing a personality disorder, the clinician must consider the ethnic, cultural, and social background of the individual. Personality disorders should not be confused with problems associated with cultural adaption following immigration or with the expression of habits, customs, or religious and political values by the individual's culture of origin.
  • Certain personality disorders, such as antisocial personality disorder) are diagnosed much more frequently in males. Others personality disorders, such as borderline, histrionic, and dependent personality disorders are diagnosed more frequently in females. Although this may reflect true differences in prevalence between genders, it is important to not overdiagnose or underdiagnose personality disorders because of social stereotypes about typical gender roles and behaviors.
  • Personality change due to another medical condition
    • When personality changes occur due to the physiological or neuropsychiatric effects of another medical condition (e.g. - a traumatic brain injury or brain metastases), this diagnosis should be used instead.
  • Other mental disorders and personality traits
    • Many of the criteria for personality disorders also describe features (e.g. - suicidal behaviour, suspiciousness, constricted affect, impulsivity) that are similar to other mental disorders. Thus, a personality disorder should be diagnosed only when the features appeared before early adulthood, are typical of the individual's long-term functioning, and do not occur exclusively during an episode of another mental disorder. It can be difficult to distinguish personality disorders from persistent mental disorders such as persistent depressive disorder that have an early onset and an enduring, relatively stable course. Other personality disorders can also exist on a spectrum or continuum of symptoms in relation to other mental disorders:
    • Personality disorders must also be differentiated from personality traits that do not reach the threshold for a personality disorder. Personality traits only become a disorder when these features becoming inflexible, maladaptive, and persistive, and cause significant functional impairment or subjective distress.
    • For the cluster A personality disorders (paranoid, schizoid, and schizotypal) that may be related to the psychotic disorders, there are exclusion criterion that require the pattern of behaviors to not have occurred exclusively during the course of schizophrenia, a bipolar or depressive disorder with psychotic features, or another psychotic disorder.
    • When personality changes emerge and persist after an individual has been exposed to extreme stress or trauma, a diagnosis of PTSD should be considered.
    • One should be cautious about diagnosing personality disorders during an episode of an anxiety disorder, because these disorders can mimic personality traits on cross-sectional observation.
    • One should be cautious about diagnosing personality disorders during an episode of a depressive disorder, because these disorders can mimic personality traits on cross-sectional observation.
    • In individuals with a substance use disorder, a personality disorder diagnosis should not be made based on behaviors stemming from a substance intoxication or withdrawal. Additionally behaviours (e.g. - antisocial behavior) that are associated with perpetuating substance use should not be used to make the diagnosis of a personality disorder.
Cluster A ("Odd, Eccentric")
Paranoid Personality Disorder
Paranoid personality disorder is characterized by pervasive distrust or suspiciousness of others such that their motives are interpreted as malevolent. It is characterized by a pattern of distrust and suspiciousness of others.
Schizoid Personality Disorder
Schizoid personality disorder is characterized by a lack of interest in social relationships (and happy about it), a tendency towards a solitary or sheltered lifestyle, secretiveness, emotional coldness, and apathy.
Schizotypal Personality Disorder
Schizotypal personality disorder is characterized by pervasive patterns of “strange” or “odd” behavior, appearance, or “magical” thinking. There is no history of psychosis or schizophrenia.
Cluster B ("Dramatic, Emotional, Erratic")
Antisocial Personality Disorder
Antisocial personality disorder is characterized by a pattern of disregard for the rights of others and engagement in unlawful activities.
Borderline Personality Disorder (BPD)
Borderline personality disorder is characterized by emotional dysregulation, patterns of unstable interpersonal relationships and high impulsivity.
Histrionic Personality Disorder
Histrionic personality disorder is characterized by flamboyant behaviour, attention-seeking, and displays of excessive emotions (may be shallow or shift rapidly). May use physical appearance or sexuality to draw attention, and also concerned with appearance.
Narcissistic Personality Disorder
Narcissistic personality disorder is characterized by a grand sense of own importance and are very sensitive to criticism. Rarely able to empathize with others. Characterized by arrogance, need for admiration, and tendency to exploit others.
Cluster C ("Anxious, Fearful")
Avoidant Personality Disorder
Avoidant personality disorder is characterized by being timid and shy, but wishing to have friends. Due to fears of being uncomfortable and afraid of rejection or criticism, they avoid social contact.
Dependent Personality Disorder
Dependent personality disorder is characterized by fear separation and a tendency to be indecisive and unable to take initiative. They have difficulty expressing disagreement because they fear abandonment.
Obsessive-Compulsive Personality Disorder (OCPD)
Obsessive-compulsive personality disorder is characterized by being perfectionistic, inflexible, and unable to express warm, tender feelings. They are preoccupied with details and rules and do not appreciate changes in routine.