Antidepressant medications v. cognitive therapy in people with depression with or without personality disorder

Background There is conflicting evidence about comorbid personality pathology in depression treatments. Aims To test the effects of antidepressant drugs and cognitive therapy in people with depression distinguished by the presence or absence of personality disorder. Method Random assignment of 180 out-patients with depression to 16 weeks of antidepressant medication or cognitive therapy. Random assignment of medication responders to continued medication or placebo, and comparison with cognitive therapy responders over a 12-month period. Results Personality disorder status led to differential response at 16 weeks, 66% v. 44% (antidepressants v. cognitive therapy respectively) for people with personality disorder, and 49% v. 70% (antidepressants v. cognitive therapy respectively) for people without personality disorder. For people with personality disorder, sustained response rates over the 12-month follow-up were nearly identical (38%) in the prior cognitive therapy and continuation-medication treatment arms. People with personality disorder withdrawn from medication evidenced the lowest sustained response rate (6%). Despite the poor response of people with personality disorder to cognitive therapy, nearly all those who did respond sustained their response. Conclusions Comorbid personality disorder was associated with differential initial response rates and sustained response rates for two well-validated treatments for depression. Declaration of interest R.C.S has received grant support from GlaxoSmithKline Pharmaceuticals. Funding detailed in Acknowledgements.