The significance of personality disorder and traits in short-term psychodynamic and cognitive behavioral therapy for major depression

BACKGROUND: Research has shown inconsistent results regarding the impact of personality disorder (PD) on psychotherapy outcomes for depression. There is a scarcity of studies comparing cognitive behavioral therapy (CBT) with short‐term psychodynamic therapy (STPP). This study aimed to compare outcome of STPP and CBT in depressed patients with and without PD and investigate whether PD or specific PD traits differentially affected outcome in STPP and CBT. METHODS: One hundred outpatients with major depression (PD, n=28; NoPD, n=72) were randomized to STPP or CBT and followed up after 28 weeks. PD was assessed by semi‐structured interview (SCID‐II) which indicated mild to moderate severity of PD. Primary outcome measures were Hamilton Depression Rating Scale and Beck Depression Inventory‐II, secondary outcome measures were the Global Functioning Scale, Work and Social Adjustment Scale and Generalized Anxiety Disorder 7. Statistics comprised bivariate analyses and multivariate linear regression. RESULTS: Effect sizes for primary and secondary outcomes were large for both the PD and NoPD groups, with no significant difference in clinical status between the groups after 28 weeks. The presence of a PD diagnosis did not moderate outcome of STPP versus CBT, but the interaction between paranoid traits and treatment showed a significant effect in favor of STPP. CONCLUSIONS: The results indicate that co‐occurring mild to moderate personality pathology should not be a barrier to standard psychotherapies for patients with depression. More studies are needed to investigate whether type and complexity of personality pathology differentially affect short‐ and longer‐term outcomes of different psychotherapies for depressed patients.