Major depressive disorder (MDD) is one of the most common psychiatric conditions and often remains difficult to treat effectively. Many patients continue to experience residual symptoms or relapse even after receiving established forms of psychotherapy. This study tests whether targeting specific psychological mechanisms can improve outcomes for people with depression. We compare two novel group therapies: (1) Expectation-Focused Psychotherapeutic Intervention (EFPI), which aims to modify rigid, negative expectations that maintain depressive symptoms, and (2) Reward Enhancement and Activation Therapy (REACT), which focuses on increasing sensitivity to positive experiences and strengthening reward-related learning. Both are delivered in a group format to foster peer support and shared learning.
A total of 150 adults with a current MDD diagnosis will be randomly assigned to EFPI, REACT, or a waiting-list control. Participants in the intervention groups receive 10 group sessions over five weeks. Waiting-list participants complete baseline and 3-month follow-up assessments before being offered standard treatment options.
Clinical outcomes are assessed at baseline, immediately after treatment, and at 3- and 6-month follow-ups (for the intervention groups). Primary outcomes are reductions in depressive symptoms measured by clinician ratings and self-report questionnaires. Secondary outcomes include changes in expectation processes and reward sensitivity.
In addition, functional MRI (fMRI) tasks examine brain mechanisms related to expectation updating and reward processing pre- and post-intervention, to help identify neural changes that may underlie symptom improvement.
By directly addressing dysfunctional expectations and reduced reward sensitivity, this study seeks to provide evidence for more targeted psychotherapeutic approaches. If successful, the results may support more personalized treatments and better long-term outcomes in MDD.
Age: 18-80 years
Current diagnosis of major depressive disorder (MDD) according to DSM-5, confirmed by structured clinical interview (e.g., DIPS)
Hamilton Depression Rating Scale (HAMD-21) score ≥ 9
Ability to attend group therapy sessions (2×/week for 5 weeks)
Current or lifetime diagnosis of bipolar disorder, psychotic disorder, or primary substance use disorder
High acute suicide risk requiring immediate intervention
Severe neurological disorder, brain injury, or contraindications for MRI (e.g., metal implants, claustrophobia)
Ongoing psychotherapy or initiation of a new antidepressant medication within the past 4 weeks
Philipps University Marburg
Lead sponsor
German Research Foundation
Collaborator