Different types of psychotherapy have been shown to be successful in treating personality disorders in younger age groups. Nevertheless, well-powered, randomized controlled trials evaluating effectiveness of these therapies in older are lacking. That is why we set up the first randomized controlled trial worldwide into the effect and cost-effectiveness of psychotherapy in older patients with a personality disorder.

We randomized 145 patients (mean age 68 years, range 60 – 80, 65% females) with a cluster B and/or C personality disorder to either group schema therapy enriched with psychomotor therapy (GST+PMT) or to usual care (UC) in specialized geriatric mental health care. The effects were measured after 6 months (end of therapy) and 12 and 18 months (one-year follow-up). Primary outcome measure was psychological distress, as measured with the 53-item Brief Symptom Inventory (BSI-53). Secondary outcome measures were mental well-being, assessed with the Warwick-Edinburgh Mental Well-being Scale, and personality functioning assessed with the Severity Indices of Personality Problems – Short Form (SIPP-SF). Intention to treat analyses using linear mixed models were applied to compare GST+PMT with UC.

Group schema therapy significantly outperformed usual care with an medium effect-size of 0.4 post-treatment, which faded out to a small effect-size of 0.2 at the end of follow-up on the primary outcome parameter. Interestingly, the lower effect-size during follow-up could be explained by a slower treatment response in the usual care condition as post-treatment results of schema therapy were fully maintained during follow-up. Similar results were found with respect to improvement of mental well-being and improvement of personality functioning, although effect-sizes of the latter were a little bit smaller. Age, sex, level of education, and/or cognitive functioning had no impact of these outcomes.

Schema therapy enriched with psychomotor therapy is more effective for the treatment of personality disorder in later life than usual care (which often consists of drug treatment combined with supportive nurse-led care and/or individual psychotherapy).