Patient predictors of response to cognitive behaviour therapy and interpersonal psychotherapy in a randomised clinical trial for depression.

Objectives: This study examined patient predictors of response to interpersonal psychotherapy (IPT) and cognitive behaviour therapy (CBT).

Method: Participants were 177 adults with a primary diagnosis of major depressive disorder randomised to 16 weekly sessions of either IPT or CBT. Pre and post treatment depressive symptomatology was assessed by an independent clinician with the Montgomery Asberg Depression Rating Scale.

Results: General predictors of response were perceived logic of therapy, recurrent depression and childhood reasons for depression (r² =.21). Only one differential predictor of treatment response was identified. Increasing comorbid personality disorder symptoms was associated with decreases in response to IPT but not CBT.

Conclusion: The results indicate that attention to specific pretreatment patient factors may enhance response to psychotherapy.