Changing treatment of patients with a recurrent depressive disordered from cognitive behavioral therapy to acceptance and commitment therapy after early non-response to treatment

For more than a third of patients with major depressive disorder (MDD) cognitive behavioral therapy (CBT) does not lead to remission. Therefore, methods to help improve treatment outcome would be desirable. Possibly, this improvement can be achieved by offering these patients recently developed new treatment options though a stepped care system. Since early reduction of symptoms are a good predictor to final treatment outcome, changing CBT to a different kind of treatment might help more patients reach remission. In this study we will compare CBT with acceptance and commitment therapy (ACT) for early non-responders to CBT. All patients will first receive 5 sessions of CBT. If there is insufficient decline of depressive symptoms, then those patients will receive either 15 more sessions of CBT or 15 sessions of ACT. During the treatment we will score their depressive symptoms and positive mental health with questionnaires every 5 sessions. The aim of this non-randomized clinical trial is to compare the effectiveness of this stepped care program and to generate recommendations for further research.

1) Early non-responders with MDD who after 5 sessions of CBT change from CBT to ACT will have fewer depressive symptoms by the end of therapy in comparison to early non-responders with MMD that continue CBT.
2) Early non-responders with MDD who after 5 sessions of CBT change from CBT to ACT will score higher on positive mental health by the end of therapy in comparison to early non-responders with MDD that continue CBT.

This study will follow patients over 20 weekly sessions. The first 5 sessions consist of CBT in both conditions. The last 15 sessions will consist of either CBT or ACT, depending on the allocated condition. Measurements with the QIDS-SR and the MHC-SF will be done at session 5, 10, 15 and 20. There is a measurement with the QIDS-SR before session 1, solely with the intention of being able to see if patients lack response to treatment at session 5. There is lack of response to treatment when the total score of the QIDS-SR dropped less than 25% by session 5. After session 20 the study will end (although treatment may continue), there is no follow up.

All participants will receive five sessions of CBT in treatment phase 1 based on a manual by Bockting, Van Rijsbergen & Huibers (2017). In treatment phase 2, the CBT-group will continue with CBT from this manual for 15 more therapy sessions. In the ACT-group patients will switch to an ACT manual (A-Tjak, 2020) for 15 more therapy sessions as soon as they enter treatment phase 2. All sessions will consist of face to face, 45-minute sessions, at HSK-groep locations.