Prevalence and classification of personality disorders

Frequency of personality disorders in the general population is reported to be between 4-12% (1)

• it has been stated that over half of patients in general psychiatric samples have a coexisting personality disorder
• personality disorders are commonly associated with other mental disorders such as depression, anxiety and substance misuse
• it is also associated with higher use of medical services, suicidal behaviour and completed suicide, and excess medical morbidity and mortality, especially in relation to cardiovascular disease. (1)

Classification:

• personality disorders are generally classified by using categories described in either of the two major classification systems: ICD 10 and DSM V
• in DSM V, perhaps the most widely used system, personality disorders are placed on Axis II whilst other psychiatric conditions (such as anxiety, depression or schizophrenia) are placed on Axis I
  • both diagnostic classifications (DSM V and ICD-10) describe ten specific personality disorders
  • the DSM V groups them into three clusters, based on descriptive similarities
    • cluster A includes paranoid, schizoid and schizotypal personality disorders (clients are likely to appear odd or eccentric)
    • cluster B includes antisocial, borderline, histrionic and narcissistic personality disorders (clients often appear dramatic, emotional or erratic)
    • cluster C includes avoidant, dependant and obsessive-compulsive personality disorders (clients are likely to appear anxious or fearful) (1)

Reference:

• (1) Gask L, Evans M, Kessler D. Clinical Review. Personality disorder. BMJ. 2013;347:f5276.