Cross-sectional analysis of depressive symptom profiles and serum C-reactive protein levels: data from the Northern Finland 1966 birth cohort

Abstract

Purpose

Individuals with depression exhibit significantly higher levels of systemic inflammation than those without depression, particularly among those with atypical depression. However, this association has been less convincing at the population level among individuals without a formal depression diagnosis but with suggestive symptoms. Our aim was to clarify this association.

Materials and methods

In a large birth cohort sample of the Finnish general population, we examined the cross-sectional association between high-sensitivity C-reactive protein (hsCRP) levels in venous blood samples and atypical/non-atypical depressive symptoms using the Beck Depression Inventory-II to screen 5443 middle-aged participants.

Results

As expected, depressive symptoms associated to elevated hsCRP-levels compared to non-depressed. Participants with the atypical subtype of depressive symptoms (n = 84) had an odds ratio (OR) of 2.59 (95% CI 1.40–4.81) for elevated hsCRP levels compared to the non-depressed group. Similarly, our findings indicate that participants with non-atypical symptoms (n = 440) also showed an OR of 1.42 (95% CI 1.05–1.92) when compared to the non-depressed group (n = 4919).

Conclusions

These results provide additional support for previous research linking depression and inflammation and add to the field with a unique and sizeable study population. Furthermore, the current results support the notion that different types of depressive symptoms may be associated with inflammatory markers in slightly different ways.

Keywords:

• Depression
• CRP
• atypical
• non-atypical
• BDI-II
• birth cohort

Acknowledgements

We express our sincerest gratitude to the field study team and study nurses who carried out all of the examinations and data collection. We would also like to thank Professor Paula Rantakallio, who launched the NFBC1966.

Disclosure Statement

None of the authors reported any biomedical financial interests or potential conflicts of interest.

Additional information

Funding

NFBC1966 received financial support from the Academy of Finland; University Hospital Oulu; the University of Oulu, Finland; the Northern Finland Health Care Foundation; the Duodecim Foundation; the Ministry of Education and Culture 86/626/2014; and the ERDF European Regional Development Fund - Well-being and Health: Research in the Northern Finland Birth Cohort 1966 (Grant no. 539/2010 A31592, 01.01.2011-31.12.2013).