[Effectiveness and clinical significance of brief dynamic psychotherapy: the Duesseldorf Short-Term Dynamic Psychotherapy Project (since 1991)].

Objectives: This study evaluates the effectiveness of short-term dynamic psychotherapy for patients with psychosomatic and personality disorders (target groups) compared to those with neurotic disorders (anxiety and depression).

Methods: Using a naturalistic design, 25 sessions of the CMP/SASB model of short-term dynamic therapy were applied to 112 outpatients. Patients with neurotic disorders constituted the control group. The effect sizes and the clinical significance were established by the end of therapy and at 6- and 12-month-follow-up.

Results: All groups improved significantly. Neurotic patients (1.6) performed better than psychosomatic and personality (.82) disorders (.94). Patients showed clinically relevant improvements in the following order: 49% of neurotic, 46% of psychosomatic and 39% of personality disorders.

Conclusions: Both target groups attained significant treatment gains and demonstrated the effectiveness of short-term dynamic psychotherapy in clinical practice. However, we found evidence that patients with personality disorders required additional psychotherapy in order to achieve essential dynamic changes.