Background: Inflammatory indices have been linked to mood disorders. We aimed to examine whether these inflammatory indices are associated with the severity of depression and anxiety as measured by Beck scores. Methods: This cross-sectional analysis included 9,704 participants aged 35–65 years from the Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) cohort study. Depression and anxiety were assessed using the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). Inflammatory indices were calculated based on hematological and biochemical parameters. Multinomial logistic regression was applied to evaluate the associations between inflammatory markers and mood disorder severity. Results: In cases of severe depression, the neutrophil-to-lymphocyte ratio (NLR), white blood cell (WBC) count, and serum high-sensitivity C-reactive protein (hs-CRP) levels were significantly higher (OR = 1.29, 1.08, and 1.01, respectively; P < 0.05) than in individuals with minimal depression. Serum hs-CRP levels were also significantly higher (OR = 0.98; 95% CI: 0.95–0.99) in participants with moderate anxiety compared with those with minimal anxiety. Conclusion: Higher levels of depression were associated with increased inflammatory hematological indices, and that the severity of depression was related to elevated levels of NLR, WBC, and hs-CRP.

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