BACKGROUNDMultisomatoform disorder is characterised by severe and disabling bodily symptoms, and pain is one of the most common and impairing of these. Furthermore, these bodily symptoms cannot be explained by an underlying organic disorder. Patients with multisomatoform disorder are commonly found at all levels of healthcare and are typically difficult to treat for physicians as well as for mental health specialists.AIMSTo test whether brief psychodynamic interpersonal therapy (PIT) effectively improves the physical quality of life in patients who have had multisomatoform disorder for at least 2 years.METHODWe recruited 211 patients (from six German academic outpatient centres) who met the criteria for multisomatoform disorder for a randomised, controlled, 12-week, parallelgroup trial from 1 July 2006 to 1 January 2009 (International Standard Randomised Controlled Trial Number ISRCTN23215121). We randomly assigned the patients to receive either 12 weekly sessions of PIT (n = 107) or three sessions of enhanced medical care (EMC, n = 104). The physical component summary of the Short Form Health Survey (SF-36) was the pre-specified primary outcome at a 9-month follow-up.RESULTSPsychodynamic interpersonal therapy improved patients' physical quality of life at follow-up better than EMC (mean improvement in SF-36 score: PIT 5.3, EMC 2.2), with a small to medium between-group effect size (d = 0.42, 95% CI 0.15-0.69, P = 0.001). We also observed a significant improvement in somatisation but not in depression, health anxiety or healthcare utilisation.CONCLUSIONSThis trial documents the long-term efficacy of brief PIT for improving the physical quality of life in patients with multiple, difficult-to-treat, medically unexplained symptoms.