Changes in pain during a depressive episode and relationship to cytokine levels in major depressive disorder

Abstract

Background

Depressed patients have an increased incidence of pain. A pathophysiological connection between depression and pain is still not revealed. Immunological activation has been found in both depression and pain. There are few studies of pain and immune activation in patients with depression, without inflammatory and autoimmune disorders.

Methods

This is a naturalistic follow-up study of 50 patients with a major depressive disorder (MDD) depressive episode, without any inflammatory or autoimmune conditions. We have previously reported on the relationship between depression and cytokine levels. In this study, we obtained data of depression, pain and cytokine levels before and after 12 weeks of depression treatment. All patients were medication-free at inclusion.

Results

At inclusion three out of four patients experienced pain, and the pain scores correlated with the depression scores. After treatment, as depression was relieved, the pain scores dropped significantly and were no longer correlated to the depression scores. There were no correlations between pain scores and cytokine levels. Pain level at inclusion did not correlate with depression treatment outcome.

Conclusion

Our findings indicate that pain is a feature of depression. Pain levels and cytokine values didn’t correlate. Pain at inclusion did not predict depression treatment outcome.

Keywords:

• Pain in depression
• cytokines
• follow-up study
• treatment outcome prediction

Acknowledgements

The authors would like to thank Vestre Viken Hospital Trust and Ringerike Psychiatric Center for funding the study. We would also like to thank the South-Eastern Norway Regional Health Authority’s (HSØ) Norwegian research network on mood disorders (NORMOOD) for initiating the study, and Tove Hæreid Otterstad for her coordination of the NORMOOD project. Further, we are indebted to Anne Skjerstein for taking care of the blood samples and the logistics. Finally, we will express our gratitude to the patients that participated in the study.

Ethical approval

The study was approved by the local Ethics Committee: Regional komite’ for medisinsk og helsefaglig forskningsetikk Sør-Øst C (REK Sør-Øst C), Postboks 1130 Blindern, NO-1130 Oslo, Norway. The patients provided written consent to participate after receiving verbal and written information regarding the study. All methods were performed in accordance with the relevant guidelines and regulations.

Author contributions

JD, OAA, HO and UFM designed the study. JD and HCDA participated in data collection. JD analyzed the data. JD wrote the first draft of the manuscript. All co-authors interpreted the data, participated in revising the manuscript and approved the final version.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The dataset generated during and analyzed during the current study are not publicly available due to requirements from Regional Ethics Committee but are available from the corresponding author on reasonable request.

Additional information

Funding

The study is fully funded by Ringerike Psychiatric Center and Vestre Viken Hospital Trust, Norway.

Notes on contributors

Johan Dahl

Johan Dahl is psychiatrist, Head of Department of Eating Disorders, Modum Bad. He holds a Ph.D. in Immune factors in Depression.

Heidi Ormstad

Heidi Ormstad holds a Ph.D. in immunology and is a professor in biomedicine. For many years, she has researched the role of the immune system in various diseases, including depression. However, most of her research has focused on different forms of fatigue. In this context, she has had a special focus on neuroimmunology and neuroinflammation. Additionally, she has been interested in biopsychosocial models of disease.

Hans Christian D. Aass

Hans Christian Dalsbotten Aass has a Ph.D. in meningococcal sepsis and focuses his research on immunology and inflammation. He has been the Core Manager for the Flow Cytometry Core Facility at OUS, Ullevål, since 2005, and is the Vice Chairman of the Norwegian Society of Flow Cytometry since 2012.

Ulrik Fredrik Malt

Ulrik Fredrik Malt is a professor of psychiatry and psychosomatic medicine (emeritus), Faculty of Medicine, University of Oslo and was Head of Department of Psychosomatic Medicine, The National hospital (Rikshospitalet) from 1987-2013. His main research interest is mood disorder, in particular bipolar spectrum disorder, psychosomatic medicine, PTSD and psychopharmacology.

Ole A. Andreassen

Ole A. Andreassen is a Professor in psychiatry, director of the NORMENT Centre, focusing on translational research from disease mechanisms to clinical impact. Has contributed to better understanding of causal factors of severe mental disorders, including immune factors, and recently focusing on large Nordic biobank and registry data for developing tools for precision psychiatry.