Van Bronswijk SC et al. – This study evaluated the effects of personality disorder (PD) features on treatment continuation and effectiveness in cognitive therapy (CT) and interpersonal psychotherapy (IPT) for major depressive disorder (MDD). No negative impact of PD on treatment retention and effectiveness for CT and IPT for MDD was identified. Treatment could be optimized on replication with cluster A PD features.

Methods

• Depressed outpatients were randomized to CT (n = 72) and IPT (n = 74).
• Depression severity was measured as the primary outcome with the Beck Depression Inventory–II (BDI–II) at baseline, 3 months, at the start of each therapy session, and monthly during the 5 months follow–up.

Results

• Comorbid PD and PD features did not affect dropout.
• Irrespective of the treatment received, there was no negative effect of PD on BDI–II change and remission rates.
• Higher dependent PD features predicted overall lower BDI–II scores during treatment, which did not sustain through follow–up for both therapies.
• Treatment outcome could be moderated with cluster A PD features.
• High cluster A PD features had greater BDI–II reductions in patients treated with CT.