Cognitive analytic therapy for personality disorder: randomised controlled trial

Background Cognitive analytic therapy (CAT) is a theoretically coherent approach developed to address common processes underlying personality disorders, but is supported by limited empirical evidence. Aims To investigate the effectiveness of time-limited CAT for participants with personality disorder. Method A service-based randomised controlled trial (trial registration: ISRCTN79596618) comparing 24 sessions of CAT (n=38) and treatment as usual (TAU) (n=40) over 10 months for individuals with personality disorder. Primary outcomes were measures of psychological symptoms and interpersonal difficulties. Results Participants receiving CAT showed reduced symptoms and experienced substantial benefits compared with TAU controls, who showed signs of deterioration during the treatment period. Conclusions Cognitive analytic therapy is more effective than TAU in improving outcomes associated with personality disorder. More elaborate and controlled evaluations of CAT are needed in the future.