CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies.
BACKGROUND: Inflammatory markers are raised in cross-sectional studies of depressed patients and may represent an important mediating factor for behaviour, neural plasticity and brain structure. METHODS: We undertook a systematic review of longitudinal studies, investigating whether raised inflammat...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2013
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| _version_ | 1826266366670274560 |
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| author | Valkanova, V Ebmeier, K Allan, C |
| author_facet | Valkanova, V Ebmeier, K Allan, C |
| author_sort | Valkanova, V |
| collection | OXFORD |
| description | BACKGROUND: Inflammatory markers are raised in cross-sectional studies of depressed patients and may represent an important mediating factor for behaviour, neural plasticity and brain structure. METHODS: We undertook a systematic review of longitudinal studies, investigating whether raised inflammatory markers indicate an increased risk of subsequent depressive symptoms. We searched three databases (1970-2012) for longitudinal studies with repeat data on CRP or IL-6 levels and subsequent depressive symptoms. We calculated effect sizes using a mixed-effects model, with separate meta-analyses for inflammatory markers and age groups. RESULTS: We identified eight papers for CRP (14,832 participants) and three for IL-6 (3695 participants). There was a significant association between increased CRP and depressive symptoms (weighted-mean effect size 'unadjusted r'=0.069, p<0.0005; 'adjusted r'=0.046, p<0.0005), with moderate heterogeneity between studies (Q=11.21, p=0.08, I(2)=46.5). For IL-6 the weighted-mean effect size was smaller ('unadjusted r'=0.045, p-value=0.007; 'adjusted r'=0.097, p-value=0.06). LIMITATIONS: The meta-analysis was based on a relatively small number of studies (particularly for IL-6) and only two inflammatory markers. There was moderate heterogeneity between studies and some evidence of publication bias. CONCLUSIONS: Raised inflammatory markers have a small but significant association with the subsequent development of depressive symptoms. This is a robust effect which remains significant after adjustment for age and a wide range of factors associated with risk for depression. Our results support the hypothesis that there is a causal pathway from inflammation to depression. |
| first_indexed | 2024-03-06T20:37:49Z |
| format | Journal article |
| id | oxford-uuid:33388f12-d1df-47c4-b0f9-3cc8d9cb7836 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:37:49Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | oxford-uuid:33388f12-d1df-47c4-b0f9-3cc8d9cb78362022-03-26T13:19:01ZCRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:33388f12-d1df-47c4-b0f9-3cc8d9cb7836EnglishSymplectic Elements at Oxford2013Valkanova, VEbmeier, KAllan, CBACKGROUND: Inflammatory markers are raised in cross-sectional studies of depressed patients and may represent an important mediating factor for behaviour, neural plasticity and brain structure. METHODS: We undertook a systematic review of longitudinal studies, investigating whether raised inflammatory markers indicate an increased risk of subsequent depressive symptoms. We searched three databases (1970-2012) for longitudinal studies with repeat data on CRP or IL-6 levels and subsequent depressive symptoms. We calculated effect sizes using a mixed-effects model, with separate meta-analyses for inflammatory markers and age groups. RESULTS: We identified eight papers for CRP (14,832 participants) and three for IL-6 (3695 participants). There was a significant association between increased CRP and depressive symptoms (weighted-mean effect size 'unadjusted r'=0.069, p<0.0005; 'adjusted r'=0.046, p<0.0005), with moderate heterogeneity between studies (Q=11.21, p=0.08, I(2)=46.5). For IL-6 the weighted-mean effect size was smaller ('unadjusted r'=0.045, p-value=0.007; 'adjusted r'=0.097, p-value=0.06). LIMITATIONS: The meta-analysis was based on a relatively small number of studies (particularly for IL-6) and only two inflammatory markers. There was moderate heterogeneity between studies and some evidence of publication bias. CONCLUSIONS: Raised inflammatory markers have a small but significant association with the subsequent development of depressive symptoms. This is a robust effect which remains significant after adjustment for age and a wide range of factors associated with risk for depression. Our results support the hypothesis that there is a causal pathway from inflammation to depression. |
| spellingShingle | Valkanova, V Ebmeier, K Allan, C CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. |
| title | CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. |
| title_full | CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. |
| title_fullStr | CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. |
| title_full_unstemmed | CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. |
| title_short | CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. |
| title_sort | crp il 6 and depression a systematic review and meta analysis of longitudinal studies |
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