The effects of an inpatient psychotherapy program based on a psychodynamically orientated group psychotherapeutic approach in a psychiatric hospital were investigated in benzodiazepine-dependent and nondependent patients. 114 matched patients with neurotic and personality disorders were assessed at the beginning of a 4- to 8-week period: the patients were retested after 10 days and at the end of the program. The results of benzodiazepine-dependent (n = 40) and non-benzodiazepine-dependent (n = 74) patients were compared with regard to effect- and course-related variables. For the evaluation of benzodiazepine-related dissociative symptoms, the Dissociative Experience Scale was used. The effects of psychotherapy were measured with the Symptom Check List 90 (SCL-90) and the Questionnaire for the Measurement of Motivation for Psychotherapy (FMP). The results show significant differences concerning the severity of symptoms and the symptom-related course in the two groups: in most dimensions of the SCL-90, the addicted group shows significantly higher scores than the control group. These differences were accentuated on retest after 10 days, which can be accounted for by the withdrawal syndrome of the benzodiazepine-dependent group. Nevertheless, the psychotherapeutic outcome, measured by the difference between the initial and the final scores, shows no significant difference. The results are discussed with regard to the importance of benzodiazepine addiction and dissociative phenomena during inpatient psychotherapy.