Stress, depression, and the therapeutic alliance as mediators on the outcome of brief psychodynamic-interpersonal psychotherapy for multisomatoform disorder.

The aim of this study was to identify and explore mediators of psychodynamic-interpersonal psychotherapy (PIT) on treatment outcome in multisomatoform disorders (MSD). Data from 164 patients with MSD who took part in a randomized control trial of PIT ( Stress partially mediated the effect of PIT vs. EMC on the follow-up outcome. PIT (as compared to EMC) led to lower post-treatment stress-levels, which in turn led to higher physical quality of life at follow-up. Neither depression nor the alliance had a mediating effect. Stress mediated the outcome of PIT for MSD. Future studies are needed to extend the scope of research regarding which specific psychotherapeutic mechanisms of change are beneficial in PIT treatment of MSD patients.