Multimodal psychodynamic psychotherapy induces normalization of reward related activity in somatoform disorder

Objectives. Somatoform disorder patients demonstrate a disturbance in the balance between internal and external information processing, with a decreased focus on external stimulus processing. We investigated brain activity of somatoform disorder patients, during the processing of rewarding external events, paying particular attention to the effects of inpatient multimodal psychodynamic psychotherapy. Methods. Using fMRI, we applied a reward task that required fast reactions to a target stimulus in order to obtain monetary rewards; a control condition contained responses without the opportunity to gain rewards. Twenty acute somatoform disorder patients were compared with twenty age-matched healthy controls. In addition, 15 patients underwent a second scanning session after participation in multimodal psychodynamic psychotherapy. Results. Acute patients showed diminished hemodynamic differentiation between rewarding and non rewarding events in four regions, including the left postcentral gyrus and the right ventroposterior thalamus. After multimodal psychodynamic psychotherapy, both regions showed a significant normalization of neuronal differentiation. Conclusion. Our results suggest that diminished responsiveness of brain regions involved in the processing of external stimuli underlies the disturbed balance of internal and external processing of somatoform disorder patients. By providing new approaches to cope with distressing events, multimodal psychodynamic psychotherapy led to decreased symptoms and normalization of neuronal activity.