Current classifications of personality disorders do not classify severity despite clinical practice favouring such descriptions.
To assess whether an existing measure of severity of personality disorder predicted clinical pathology and societal dysfunction in a community sample.
UK national epidemiological study in which personality status was measured using the screening version of the Structured Clinical Interview for DSM–IV Personality Disorders (SCID–II) and reclassified to five levels using a modified severity index. Associations between levels of severity of personality pathology and social, demographic and clinical variables were measured.
Of 8391 individuals interviewed and their personality status assessed, only a minority (n = 1933, 23%) had no personality pathology. The results supported the hypothesis. More severe personality pathology was associated incrementally with younger age, childhood institutional care, expulsion from school, contacts with the criminal justice system, economic inactivity, more Axis I pathology and greater service contact (primary care and secondary care, all P<0.001). Significant handicap was noted among people with even low levels of personality pathology. No differences contradicted the main hypothesis.
A simple reconstruction of the existing classification of personality disorder is a good predictor of social dysfunction and supports the development of severity measures as a critical requirement in both DSM–V and ICD–11 classifications.
- © 2010 Royal College of Psychiatrists