On Monday 7th of September Joost Gülpen will defend his PhD thesis titled ‘Between Recovery and Relapse. Examining Partial Remission and Cognitive Functioning in Major Depressive Disorder’ in the Agnietenkapel of the University of Amsterdam at 16:00h.
Although effective treatments for depression are available, around one-third of patients continue to experience considerable residual symptoms after a depressive episode. This phase, known as partial remission, is associated with a wide range of adverse outcomes, including impaired functioning, increased suicide risk, and a substantially increased risk of relapse, but has received relatively little attention in research and clinical practice. Joost Gülpen explains: “We wanted to better understand how we can improve treatment and outcomes for this at-risk group.”
In this thesis, Joost examined partial remission as a distinct and important phase of major depressive disorder (MDD), with a particular focus on optimising treatment and understanding the role of cognitive functioning.
Thesis in short
This research focused on two main questions: which treatments are effective for people in partial remission of depression? And what role does cognitive functioning play in recovery and relapse? First, Joost and colleagues systematically evaluated the effectiveness of available treatments and examined whether psychological interventions work equally well for different types of patients. For this, they used patient-level data from 16 RCTs. Second, using 20 years of follow-up data, they investigated whether cognitive functioning influences the long-term course of depression. And they investigated whether recurrent depression, in turn, leads to cognitive change. Finally, in a randomised controlled trial (RCT), the researchers examined whether adding Neurocognitive Remediation Therapy to Preventive Cognitive Therapy could further reduce residual symptoms and prevent relapse.
Psychological interventions
In his thesis, Joost has found that psychological interventions can meaningfully improve outcomes for people in partial remission of depression. They reduce residual depressive symptoms and increase the likelihood of reaching full remission. Importantly, psychological relapse-prevention interventions were associated with an approximately 40% lower risk of relapse over 12 months. These benefits were found across a broad range of clinical and demographic patient characteristics. This suggests that these interventions should be offered broadly rather than only to specific subgroups.
Cognitive functioning
Regarding cognitive functioning, our findings were somewhat unexpected. Over a 20-year period, we found no evidence that poorer cognitive functioning predicted a worse course of depression, or that having more depressive episodes resulted in progressive cognitive decline. Finally, in an RCT (HERSTEL-study), adding Neurocognitive Remediation Therapy to Preventive Cognitive Therapy did not further improve cognitive functioning, residual depressive symptoms, or relapse prevention over 12 months.
What have we learned?
Partial remission of depression deserves more attention in clinical practice. Improvement is not necessarily the same as full recovery/remission and it is worthwhile to offer additional treatment. Our findings show that effective psychological interventions are already available to help reduce residual symptoms and better prevent relapse. Joost adds: “Rather than routinely adding Neurocognitive Remediation Therapy, the priority should be to make these existing psychological interventions more accessible to people who have not yet fully recovered.”
On Monday 7th of September Joost Gülpen will defend his PhD thesis titled ‘Between Recovery and Relapse. Examining Partial Remission and Cognitive Functioning in Major Depressive Disorder” in the Agnietenkapel of the University of Amsterdam at 16:00h. Joost’s thesis is supervised by Prof. C.L.H. Bockting and Prof. D.A.J.P. Denys, and co-supervised by Dr E.A.M. van Dis and Dr G.J. Geurtsen. More information on this dissertation can be found on the website of UvA.
Joost Gülpen (31 years) worked as a PhD candidate at the department of Psychiatry at Amsterdam UMC, where he currently works as a postdoctoral researcher. Alongside his research, he is training to become a healthcare psychologist (GZ-psycholoog), combining clinical work with research at the department.
