Effectiveness of outpatient, day hospital, and inpatient psychotherapeutic treatment for patients with cluster B personality disorders.

Background: For patients with cluster B personality disorders there is no consensus regarding the optimal treatment setting. The aim of this study was to compare the effectiveness of different psychotherapeutic settings for patients with cluster B personality disorders, i.e. outpatient, day hospital, and inpatient treatment.

Methods: The study was conducted between March 2003 and June 2008 in 6 mental health care centres in the Netherlands, with a sample of 207 patients with a DSM-IV-TR axis II cluster B diagnosis. Patients were assigned to 3 different settings of psychotherapeutic treatment and effectiveness was assessed at 18 months after baseline. An intention-to-treat analysis was conducted for psychiatric symptoms (Brief Symptom Inventory), psychosocial functioning (Outcome Questionnaire-45), and quality of life (EQ-5D), using multilevel statistical modelling. As the study was non-randomised, the propensity score method was used to control for initial differences.

Results: Patients in all 3 settings improved significantly in terms of psychiatric symptoms, social and interpersonal functioning, and quality of life 18 months after baseline. The inpatient group showed the largest improvements. The comparison of outpatient and inpatient treatment regarding psychiatric symptoms showed a marginally significant result (p = 0.057) in favour of inpatient treatment.

Conclusions: Patients with cluster B personality disorders improved in all investigated treatment settings, with a trend towards larger improvements of psychiatric symptoms in the inpatient setting compared to the outpatient setting. Specialised inpatient treatment should be considered as a valuable treatment option for cluster B personality disorders, both in research and in clinical practice.