Interpersonal psychotherapy as add-on for treatment-resistant depression: A pragmatic randomized controlled trial.

Background: Treatment-resistant depression (TRD) is an extremely prevalent clinical condition. Although Interpersonal Psychotherapy (IPT) is an established treatment for uncomplicated depression, its effectiveness has never before been studied in patients with TRD in real-world settings. We investigate IPT as an adjunct strategy to treatment as usual (TAU) for TRD patients in a pragmatic, randomized, controlled trial.