Common Factors of Psychotherapy in Inpatients With Major Depressive Disorder: A Pilot Study

Background: Psychotherapeutic interventions share common factors, which might contribute to treatment success independent of the type of psychotherapy. Previous research on common factors of psychotherapy was mostly conducted in outpatients and covered the development of common factors throughout a therapy over months or years. However, the role of common factors for the psychotherapeutic treatment success in inpatients during their hospital stay has not been addressed so far. The present research therefore aimed to explore changes of the common factors within a short-term stay at the psychiatric hospital for inpatients with major depressive disorder (MDD) and their relation to treatment outcome. Method: We developed a standardized manualized individual cognitive-behavioral psychotherapy (SMiCBT) for depression. The SMiCBT treatment lasted 4 weeks with eight therapy sessions. Following each treatment session, patients and therapists separately completed the questionnaire of "Stundenbogen für die Allgemeine und Differentielle Einzel-Psychotherapie" (STEP) to assess common factors from the perspective of the patient and the therapist. Severity of depression was also measured by the German version of the "Beck Depression Inventory" (BDI-II) before and after the treatment (SMiCBT). We conducted multilevel analysis for the longitudinal data for each scale of the STEP. Results: We found an improvement in the severity of depressive symptoms across the treatment period according to BDI-II scores. Regarding the STEP scales, motivational clarification and problem-solving scores increased over the treatment period for both patient and therapist perspectives. This was not the case for the scale therapeutic relationship. Furthermore, baseline levels of motivational clarification and problem solving were related to the treatment response. Limitations: The results have to be interpreted with care because of the small sample with MDD and the lack of a control group for comparison of treatment outcome. Conclusion: Our data demonstrate that common factors improve within a short-term psychotherapy in inpatients with MDD. Most importantly, our research highlights the distinguished role of motivational clarification and problem solving for the improvement of depressive symptoms during short-term psychotherapy in inpatient settings.