Abstract
Introduction Depression is a common mental health condition that can occur alongside other physical or nutritional problems. This study examines the relationship between iron deficiency and the severity of depressive symptoms. Aims To investigate the correlation between iron deficiency anaemia (IDA) and depression severity and to assess the influence of socio-demographic factors. Methods and materials A cross-sectional study was conducted on 200 patients aged 16-60 years with depression (ICD-11) and confirmed IDA (haemoglobin <13 g/dl in males, <12 g/dl in females, mean corpuscular volume (MCV) <80 fL). Depression severity was assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS). Sociodemographic data, complete blood counts, and peripheral smears were obtained. Data analysis included descriptive statistics, Spearman's correlation, and multivariable regression. Data were analysed using R (v4.0.2; R Foundation for Statistical Computing, Vienna, Austria) with descriptive statistics, the Shapiro-Wilk test for normality, and Spearman's correlation. A p-value <0.05 was considered statistically significant. Results Participants had a mean age of 40.1 ± 4.2 years; females comprised 64.5% (n=129), and 81% (n=162) resided in rural areas. Severe depression (MADRS >34) was observed in 55.5% (n=111) of participants. Most blood smears (n=141; 70.5%) showed a microcytic hypochromic pattern. Significant negative correlations were found between MADRS scores and haemoglobin (rho = -0.45, p <0.001), MCV (rho = -0.45, p <0.001), mean corpuscular haemoglobin (MCH) (rho = -0.31, p <0.001), and mean corpuscular haemoglobin concentration (MCHC) (rho = -0.34, p <0.001). Regression analysis confirmed haemoglobin as an independent predictor of depression severity (β = -1.58, p <0.001). Conclusion IDA is significantly associated with greater depression severity in rural Indian patients. Screening and addressing anaemia alongside antidepressant therapy may provide a cost-effective strategy to improve mood outcomes, highlighting the need for integrated management approaches.