On the 11th of March 2026, Sarah Vreijling will defend her PhD thesis titled ‘Personalized care for immuno-metabolic depression. A whole-body approach to depression’, in the Auditorium of the Vrije Universiteit Amsterdam at 11:45h.
Depression increases the risk of subsequent cardiometabolic conditions, partly through its negative impact on biological mechanisms such as immune and metabolic processes. However, not all individuals with depression experience these biological changes. Recent research highlights that immune and metabolic dysregulation is more common in people with certain depressive symptoms, such as increased appetite, weight gain, fatigue, and excessive sleep. Recognising immuno-metabolic depression as a biologically distinct form of depression can help explain the diversity of depressive disorders, identify those at higher cardiometabolic risk, and support more personalised approaches in psychiatry.
Sarah’s research and thesis are part of the PERCIM project. PERCIM aimed to improve personalized care for depression, with a specific focus on immuno-metabolic depression.
The main aim of this thesis is to enhance understanding of the conceptualisation of immuno-metabolic depression and to investigate its implications for personalised depression treatment. First, Sarah and colleagues aimed to replicate and refine previous findings on the characterisation of immuno-metabolic depression at a larger scale and across populations at different stages of depression and immuno-metabolic health. Second, they examined whether immuno-metabolic depression may serve as a useful profile for identifying patients less likely to benefit from first-line antidepressants. Third, the researchers investigated whether lifestyle-based interventions (exercise, dietary interventions, and light therapy), that may help normalise immune and metabolic dysregulation, hold promise for individuals with immuno-metabolic depression.
Findings
On a large scale, Sarah and colleagues confirmed that symptoms of the atypical, energy-related depressive symptom profile tend to co-occur more often than other depressive symptoms. These energy-related symptoms are consistently associated with adverse metabolic health indicators, thereby reinforcing the current conceptualisation of immuno-metabolic depression.
They also found that individuals with features of immuno-metabolic depression seem to respond slightly worse to antidepressants. The use of antidepressants may even be linked to worsening of immuno-metabolic depression features. This underscores the importance of monitoring somatic health during conventional pharmacological treatments for depression and the need to explore alternative approaches.
Thirdly, the findings show that lifestyle-based interventions such as exercise, dietary strategies, and light therapy did not lead to markedly better depression outcomes in immuno-metabolic depression. However, running therapy and a food-related behavioural activation intervention were associated with reductions in immuno-metabolic depression features themselves. This indicates the potential value of exercise and dietary behavioural interventions as part of a lifestyle-based treatment approach for individuals with immuno-metabolic depression.
Precision psychiatry
This dissertation highlights the importance of recognising clinical and biological differences in depression. Immuno-metabolic depression may help identify patients at higher cardiometabolic risk and those less responsive to antidepressants. While more research is needed, physical activity and, to a lesser extent, dietary interventions show promise in reducing symptoms. Clinicians should consider lifestyle interventions as part of holistic care, supporting a move toward more personalised and integrated treatment in line with precision psychiatry.
On the 11th of March 2026, Sarah Vreijling will defend her PhD thesis titled ‘Personalized care for immuno-metabolic depression. A whole-body approach to depression’, in the Auditorium of the Vrije Universiteit Amsterdam at 11:45h. Sarah’s thesis is supervised by B.W.J.H. Penninx and F. Lamers and co-supervised by R. Jansen and A.T.F. Beekman. More information on this dissertation can be found on the website of VU Amsterdam.
Sarah Vreijling worked as a PhD candidate at the Department of Psychiatry at Amsterdam UMC, conducting research within the PERCIM project. Sarah states: “I started this research because I’ve always been deeply interested in the interconnectedness of mental and physical health. Having witnessed many people in my life struggle with depression, I feel a strong motivation to contribute to reducing its burden. I believe in the potential of integrating lifestyle interventions in mental health care, and I wanted to explore how we can incorporate these into more personalized and effective treatment approaches for depression.” Currently, Sarah works at Erasmus Medical Center in Rotterdam as a teacher in medical psychology and student coach in personal and professional development for medical students. She also works as a yoga teacher in Leiden.
