Association between serum ferritin concentrations and depressive symptoms in Japanese municipal employees

It remains unclear whether levels of body iron store are related to milder forms of depression, which are more common among apparently healthy people. We examined the association between serum ferritin concentrations and depressive symptoms among 312 men and 216 women working in two municipal offices in Japan. Depressive symptoms were assessed by using the Center for Epidemiologic Studies Depression (CES-D) scale. In men, increased prevalence of depressive symptoms (defined by using a cutoff value of ≥ 19) was significantly associated with decreased levels of serum ferritin. In age- and study-site-adjusted models, ORs (95% CIs) for depressive symptoms for men in first, second, third, and fourth quartiles of serum ferritin concentrations were 2.83 (1.01-7.94), 1.74 (0.87-3.49), 1.33 (0.71-2.47), and 1.00 (reference), respectively (p for trend=0.02). In multivariate-adjusted model, ORs (95% CIs) in first, second, third, and fourth quartiles of serum ferritin concentrations were 2.88 (0.93-8.91), 1.91 (0.90-4.05), 1.28 (0.66-2.49), and 1.00 (reference), respectively (p for trend=0.03). No significant association was detected in women. Our finding that men with lower levels of serum ferritin concentrations had a higher prevalence of depressive symptoms suggests that adverse psychological effects may be implicated in iron deficiency among middle-age Japanese workers.