Does the ICD 10 classification accurately describe subtypes of borderline personality disorder?

The aim of the paper is to explore whether the division of borderline personality disorder, as described in the DSM classification, into impulsive and borderline subtypes of emotionally unstable personality disorder in the ICD classification of personality disorder, is a valid division. The self-report questionnaire responses of 288 referrals to a personality disorder service were rated on each of the eight criteria for DSM-III-R diagnosis of borderline personality disorder. Factor analysis identified two factors; factor one closely corresponds with the borderline subtype of ICD10, whilst factor two closely corresponds with the impulsive subtype of ICD10. Criteria common to both factors unstable relationships and identity confusion - were considered core features of borderline personality disorder. The pattern of occurrence of the two factors was similar to the complex binary picture described by ICD10. However there were also differences. Firstly, identity confusion is found to be a core feature of both our factors, and this does not conform to the restriction of identity confusion to the borderline subtypes in ICD10. Secondly, we found a residual pool of undifferentiated borderline patients and a small group of pure non-impulsive borderline patients who are not currently accommodated within the ICD10 emotionally unstable personality disorder. We conclude that future classifications of this disorder should accommodate four subtypes, and suggest these subtypes have implications for treatment and further research.