Is treatment in a day hospital step-down program superior to outpatient individual psychotherapy for patients with personality disorders? 36 months follow-up of a randomized clinical trial comparing different treatment modalities.

Despite increasing interest in the development of effective treatments for patients with PDs, there is still no consensus about the optimal treatment setting for this group of patients. This study reports the 36 months follow-up of the Ullevål Personality Project (UPP) (n=113), a randomized clinical trial comparing two treatment modalities for patients with PDs: an intensive long-term step-down treatment program, consisting of short-term day hospital treatment followed by combined group and individual psychotherapy organized in a hospital setting, with "ordinary" outpatient individual psychotherapy in private practice for patients with moderate to severe PDs. Patients in both treatment groups showed improvements in several clinical measures after 36 months. However, contrary to our expectations, patients in the outpatient treatment setting improved significantly more. Possible explanations for this surprising finding are discussed. The study cannot exclude the possibility that treatment aspects other than differences in modalities could explain some of the differential effectiveness (e.g. differences between therapists).