In a prospective multicenter study of Crohn disease patients, the influence of psychotherapy on the course of the disease and on psychosocial variables (anxiety, depression, life satisfaction and data of the PSKB) was studied. Psychodynamic oriented psychotherapy was provided in addition to a standardized medical treatment and took place during the first year of the two-year observation period. 108 of 488 patients were recruited and randomly assigned to the psychotherapy and the control group. 84 patients completed the somatic and 81 the psychosocial follow up. 23% of the control group and 30% of the psychotherapy group showed episode-free courses, 29% and 17% respectively underwent surgery (worst outcome group). The ranking and comparisons of the disease course showed no significant difference (p = 0.125) between psychotherapy and control group. The psychosocial variables also showed no differences between these groups. Subjectively, the patients report favourable effects to psychotherapy.