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Meta-Analysis
. 2019 Sep;49(12):1958-1970.
doi: 10.1017/S0033291719001454. Epub 2019 Jul 1.

Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels

Emanuele Felice Osimo  1   2   3 , Luke James Baxter  4 , Glyn Lewis  5 , Peter B Jones  1   2 , Golam M Khandaker  1   2
Affiliations
Meta-Analysis

Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels

Emanuele Felice Osimo et al. Psychol Med. 2019 Sep.

Abstract

Background: Peripheral low-grade inflammation in depression is increasingly seen as a therapeutic target. We aimed to establish the prevalence of low-grade inflammation in depression, using different C-reactive protein (CRP) levels, through a systematic literature review and meta-analysis.

Methods: We searched the PubMed database from its inception to July 2018, and selected studies that assessed depression using a validated tool/scale, and allowed the calculation of the proportion of patients with low-grade inflammation (CRP >3 mg/L) or elevated CRP (>1 mg/L).

Results: After quality assessment, 37 studies comprising 13 541 depressed patients and 155 728 controls were included. Based on the meta-analysis of 30 studies, the prevalence of low-grade inflammation (CRP >3 mg/L) in depression was 27% (95% CI 21-34%); this prevalence was not associated with sample source (inpatient, outpatient or population-based), antidepressant treatment, participant age, BMI or ethnicity. Based on the meta-analysis of 17 studies of depression and matched healthy controls, the odds ratio for low-grade inflammation in depression was 1.46 (95% CI 1.22-1.75). The prevalence of elevated CRP (>1 mg/L) in depression was 58% (95% CI 47-69%), and the meta-analytic odds ratio for elevated CRP in depression compared with controls was 1.47 (95% CI 1.18-1.82).

Conclusions: About a quarter of patients with depression show evidence of low-grade inflammation, and over half of patients show mildly elevated CRP levels. There are significant differences in the prevalence of low-grade inflammation between patients and matched healthy controls. These findings suggest that inflammation could be relevant to a large number of patients with depression.

Keywords: C-reactive protein; CRP; depression; immunopsychiatry; inflammation; low-grade inflammation; meta-analysis; mood; prevalence; review.

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Figures

Fig. 1.
Fig. 1.
Prevalence of low-grade inflammation (CRP >3 mg/L) in depressed patients.
Fig. 2.
Fig. 2.
Odds ratio for low-grade inflammation (CRP >3 mg/L) in depressed patients compared with matched controls.
Fig. 3.
Fig. 3.
Prevalence of elevated CRP (>1 mg/L) in depressed patients.
Fig. 4.
Fig. 4.
Odds ratio for elevated CRP (>1 mg/L) in depressed patients compared with matched controls.
See this image and copyright information in PMC

References

    1. Almeida OP, Flicker L, Norman P, Hankey GJ, Vasikaran S, van Bockxmeer FM and Jamrozik K (2007) Association of cardiovascular risk factors and disease with depression in later life. The American Journal of Geriatric Psychiatry 15, 506–513. - PubMed
    1. Benedetti F, Lucca A, Brambilla F, Colombo C and Smeraldi E (2002) Interleukine-6 serum levels correlate with response to antidepressant sleep deprivation and sleep phase advance. Progress in Neuro-psychopharmacology and Biological Psychiatry 26, 1167–1170. - PubMed
    1. Benros ME, Waltoft BL, Nordentoft M, Østergaard SD, Eaton WW, Krogh J and Mortensen PB (2013) Autoimmune diseases and severe infections as risk factors for mood disorders: a nationwide study. JAMA Psychiatry 70, 812–820. - PubMed
    1. Cáceda R, Griffin WST and Delgado PL (2018) A probe in the connection between inflammation, cognition and suicide. Journal of Psychopharmacology 32, 482–488. - PMC - PubMed
    1. Carvalho L, Torre J, Papadopoulos A, Poon L, Juruena M, Markopoulou K, Cleare A and Pariante C (2013) Lack of clinical therapeutic benefit of antidepressants is associated overall activation of the inflammatory system. Journal of Affective Disorders 148, 136–140. - PubMed

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