title: Critical developments in the assessment of personality disorder.
abstract: BACKGROUND
  The assessment of personality disorder is currently inaccurate, largely unreliable, frequently wrong and in need of improvement.
  
  
  OBJECTIVE
  To describe the errors inherent in the current systems and to indicate recent ways of improving personality assessment.
  
  
  METHODS
  Historical review, description of recent developments, including temporal stability, and of studies using document-derived assessment.
  
  
  RESULTS
  Studies of interrater agreement and accuracy of diagnosis in complex patients with independently established personality status using document-derived assessment (PAS-DOC) with a four personality cluster classification, showed very good agreement between raters for the flamboyant cluster B group of personalities, generally good agreement for the anxious/dependent cluster C group and inhibited (obsessional) cluster D group, but only fair agreement for the withdrawn cluster A group. Overall diagnostic accuracy was 71%.
  
  
  CONCLUSIONS
  Personality function or diathesis, a fluctuating state, is a better description than personality disorder. The best form of assessment is one that uses longitudinal repeated measures using a four-dimensional system.
authors.affiliation: Department of Psychological Medicine, Imperial College, Charing Cross Campus, St Dunstan's Road, London W6 8RP, UK. p.tyrer@imperial.ac.uk
authors.forename: Peter
authors.initials: P
authors.lastname: Tyrer
authors.forename: Natalie
authors.initials: N
authors.lastname: Coombs
authors.forename: Fatema
authors.initials: F
authors.lastname: Ibrahimi
authors.forename: Anand
authors.initials: A
authors.lastname: Mathilakath
authors.forename: Priya
authors.initials: P
authors.lastname: Bajaj
authors.forename: Maja
authors.initials: M
authors.lastname: Ranger
authors.forename: Bharti
authors.initials: B
authors.lastname: Rao
authors.forename: Raana
authors.initials: R
authors.lastname: Din
mesh_terms: D005544:Forecasting; D006801:Humans; D010552:Personality Assessment; D010554:Personality Disorders / Q000145:classification / Q000175:diagnosis*; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000639:trends