Current research on medically unexplained somatic symptoms (MUSS) shows a renewed interest in psychodynamic approaches. Patients with MUSS lack the capacity to mentalize about their feelings. They have an attachment history characterized by insecure attachment relationships. They have a personality trait that can be best described as self-critical perfectionism. Their insecure early attachment relations have had a negative impact on the development of their stress regulatory system. Staff of Psychotherapeutisch Dagcentrum, affiliated with the Department of Psychiatry of a general hospital in Tilburg, found dynamic interpersonal therapy (DIT) a suitable treatment model for the treatment program that was run for patients with MUSS. DIT was developed by Lemma, Fonagy, and Target in the UK for the individual treatment of patients suffering from depression. Subsequently, a variant of DIT was developed in order to make it suitable for application in a multidisciplinary group setting.