Zinc Deficiency and Depressive Disorders: A Hospital-Based Study in Kut Governorate, Iraq, 2022

Rezumat

Background: Studies report that 19–34% of individuals with depression exhibit treatment resistance to antidepressants, with up to 50% experiencing symptom relapse. This underscores the need for alternative therapeutic strategies, such as micronutrient supplementation, in clinical management. Zinc, a trace element integral to cognitive function, learning, and behavioral regulation, has been implicated in mood disorders. Pioneering work by Hansen et al. first highlighted correlations between serum zinc levels and depressive symptoms. Aim: This study aimed to evaluate differences in mean serum zinc concentrations between depressed and non-depressed individuals and assess the association between zinc deficiency and depression. Methods: A hospital-based cross-sectional study was conducted from May to August 2022, involving 134 participants (aged 18–70 years) recruited from the Psychiatric Unit of a Teaching Hospital in Kut Governorate, Iraq. Depression was diagnosed using DSM-5 criteria. Exclusion criteria included age <18 or >70 years, pregnancy, lactation, postpartum status, diabetes, renal/hepatic failure, gastrointestinal disorders (e.g., Crohn’s disease, ulcerative colitis), recent surgery, burns, hematologic conditions (e.g., leukemia), recent zinc supplementation (<1 week), and concurrent use of diuretics, valproate, or psychotropic medications. Results: Depressed patients exhibited significantly lower mean serum zinc levels (66.90 ± 30.51 μg/dL) compared to non-depressed subjects (108.45 ± 22.44 μg/dL; p < 0.001). Zinc deficiency was prevalent in 53.4% of depressed patients, with 23.3% showing marginal deficiency and 23.3% within normal range. In contrast, 77.9% of non-depressed participants had normal zinc levels, while 22.1% showed marginal deficiency (p < 0.05). Conclusion: Serum zinc levels are markedly reduced in depressed individuals, suggesting zinc deficiency may serve as a modifiable risk factor for depression. Zinc supplementation could offer therapeutic benefits in alleviating depressive symptoms.