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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

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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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