The impact of expectations on treatment outcomes following intensive psychotherapy in inpatients with major depression

• Positive expectations toward psychotherapy enhance inpatient depression outcomes. • High expectations of medication are linked to reduced treatment benefit. • Patients’ biomedical models are associated with belief in medication. • Psychological models are associated with belief in psychotherapy. Patients’ expectations concerning the effectiveness of treatment play a significant role in shaping clinical outcomes. These expectations are, in part, influenced by the explanatory models patients hold regarding the etiology of their illness. In the case of depression, both psychotherapeutic and pharmacological treatment options are available, each associated with distinct etiological models—psychological and biomedical, respectively. Our study aimed to examine the significance of pre-treatment expectations regarding the helpfulness of medication or psychotherapy for treatment outcomes in depression. A total of 635 inpatients diagnosed with major depressive disorder were included. Upon admission, all patients were asked to rate two statements assessing their expectations regarding the potential benefits of medication and psychotherapy. Depressive symptom severity was evaluated using the revised Beck Depression Inventory (BDI-II). Additionally, a subsample of 290 patients was queried about their beliefs concerning the etiology of their depression, including ongoing stress, metabolic imbalances in the brain, adverse childhood experiences, and genetic predisposition. Mean BDI-II scores decreased substantially from admission to discharge. Expectations of receiving help through medication were more strongly associated with biomedical explanatory models, whereas expectations of benefiting from psychotherapy were more closely linked to psychological explanations. Regression analysis revealed that the reduction in depressive symptoms was attenuated by high expectations of benefit from medication, while optimistic expectations regarding psychotherapy were associated with greater symptom improvement. Our findings suggest that fostering patients’ confidence in psychotherapy is important. Moreover, biomedical explanations for depression should not be promoted, particularly given the limited scientific evidence supporting them.