Evolutionary Systems Therapy for Obsessive-Compulsive Personality Disorder: A Five-Case Series.

Obsessive-compulsive personality disorder is the most common personality disorder, with a prevalence of approximately 6.5% in the general population. However, little is known about the effective psychotherapy for this disorder. In this case series, we employed evolutionary systems therapy to support five adults diagnosed with obsessive-compulsive personality disorder. Evolutionary systems therapy is a novel form of psychotherapy that integrates evolutionary psychopathology, compassion-focused therapy, and metacognitively oriented treatments. Primary outcome (personality pathology) was assessed monthly from baseline to follow-up. Secondary outcomes (anxiety, depression, perfectionism, self-criticism, overcontrol) were assessed at initial and final sessions. Moreover, we evaluated the feasibility of intervention (completion, attendance, adverse events). At the end of 6 months of treatment, all the participants reported reliable changes and remitted from diagnosis. These outcomes were maintained at 1-month and 3-month follow-ups. Further research is needed to provide evidence about the acceptability of evolutionary systems therapy in the treatment of obsessive-compulsive personality disorder.