The relationship between the serum C-reactive protein level and bipolar disorder

Background: The inflammatory hypothesis suggests that inflammation plays an important role in mood disorders, as evidenced by augmented levels of inflammatory markers. C-reactive protein (CRP) is an inflammatory marker that significantly affects numerous psychiatric disorders and their progression. Aim: The aim of this study was to compare serum CRP levels among patients with first episode (manic episode) bipolar 1 disorder (BD), patients with chronic (manic episode) BD, and a control group. Methods: Sixty participants were included: 20 with first-episode BD, 20 with chronic BD (defined as illness duration > 1 year and multiple manic episodes), and 20 healthy controls matched for age and sex. Serum CRP levels were measured using the Cobas CRP test. Data were analyzed using analysis of variance with post hoc least significant difference tests. Results: Mean CRP levels were significantly higher in the chronic BD group (28.17 ± 5.47 mg/L) than in the first-episode BD (1.31 ± 0.42 mg/L) and control groups (1.28 ± 0.19 mg/L) ( P < 0.001). The first-episode BD group did not differ significantly from the control group ( P = 0.799). Conclusion: Chronic BD patients exhibit significantly elevated serum CRP levels compared to first-episode and healthy individuals. These findings support the use of CRP as a probable pointer of ailment progression in bipolar disorder.