Comorbidity of borderline personality disorder with other personality disorders in psychiatric outpatients: how does it look at 2-year follow-up?

BACKGROUND: The rates of remission of comorbid personality disorders for patients with a primary borderline personality disorder (BPD) have previously only been addressed in samples of inpatients or former inpatients with BPD receiving treatment-as-usual.

AIMS: The aim of the current study was to assess the rates of remission of comorbid axis II personality disorders in a sample of 32 outpatients with a primary BPD receiving open-ended non-manualized psychotherapy.

METHODS: Structured psychiatric interviews for DSM-IV were conducted by independent assessors at intake, discharge and 2-year follow-up. Independent t-test, chi-square and McNemar analyses based on intent-to-treat were used.

RESULTS: The overall rate of comorbid axis II disorders was significantly reduced from intake to 2-year follow-up. Patients with non-remitted BPD had significantly more PD diagnoses and symptomatic distress on all outcome measures at follow-up.

CONCLUSION: Comorbid personality disorders among outpatients with BPD can be expected to remit with time and with remission of BPD. In the current sample of outpatients, comorbid paranoid, avoidant and obsessive-compulsive personality disorders at 2-year follow-up were associated with non-remitted BPD. The clinical implication of the results is that especially comorbid avoidant and obsessive-compulsive personality disorders may require specific attention in treatment of patients with BPD.