Higher levels of C-reactive protein in the acute phase of stroke indicate an increased risk for post-stroke depression: A systematic review and meta-analysis

•Post-stroke depression is one of the most common neuropsychiatric disorders with high incidence and prevalence.•Biomarkers for predicting post-stroke depression are required.•A higher level of C-reactive protein in the acute phase of stroke indicates a higher risk for post-stroke depression.•The level of C-reactive protein is a significant potential predictor of post-stroke depression. Investigations have revealed the association between inflammation and post-stroke depression (PSD). However, whether the C-reactive protein (CRP) level, a biomarker of inflammation, would affect the development of PSD is still controversial. A systematic search of databases was performed for eligible studies. Standardized Mean Difference (SMD) with 95 % Confidence Interval (CI) was used to assess the association between the CRP level in the acute phase of stroke and the risk of PSD. 13 cohort studies that involved 3536 participants were included. Combined results showed that compared with non-PSD patients, the CRP level of PSD patients was significantly higher on admission (SMD = 0.19, 95 % CI: 0.12−0.27). A subgroup analysis by classifying the assessment time of depression showed obvious differences of the CRP levels between the PSD patients who were diagnosed more than 1 month after stroke and the non-PSD (1−3 months: SMD = 0.16, 95 % CI: 0.06−0.25; >3months: SMD = 0.34, 95 % CI: 0.18−0.51). A higher level of CRP in the acute phase of stroke suggests an increased risk for PSD.