Psychiatric disorders risk in patients with iron deficiency anemia and association with iron supplementation medications: a nationwide database analysis

BACKGROUND: It has been shown that iron deficiency anemia (IDA) is associated with psychosocial consequences and psychiatric morbidity. However, the association between adults with IDA and psychiatric disorders has not been clarified. The purpose of this study was to investigate the psychiatric disorder morbidity of an IDA group in comparison with a non-IDA group and to examine the risk of psychiatric disorders in IDA patients treated with iron supplementation. METHODS: All study subjects were 20 years of age or over with newly diagnosed IDA enrolled in the Taiwan National Health Insurance Database from 2000 to 2012. We matched IDA and non-IDA subjects according to age and gender in a 1:2 ratio. Our primary outcome was diagnosis of psychiatric disorders and the patients were monitored until the end of 2013. A multivariate Cox proportional hazards regression model was used to explore the risk of psychiatric disorders in patients with IDA after adjustment for confounders, including demographic characteristics and comorbidities. RESULTS: The adjusted hazard ratios (aHRs) of psychiatric disorders was 1.52 (95% CI = 1.45–1.59) in the IDA group compared with the non-IDA group. Among the different types of psychiatric disorders, the IDA group was associated with significantly higher incidence and risks of anxiety disorders, depression, sleep disorders, and psychotic disorders (p < 0.05). Furthermore, iron supplementation in IDA subjects was associated with a significantly lower risk of psychiatric disorders compared to non-iron supplementation in IDA patients. CONCLUSIONS: Our study indicates that IDA subjects had an increased risk of psychiatric disorders, regardless of other confounders. In IDA patients, iron supplementation was associated with a decreased risk of psychiatric disorders. Moreover, IDA patients receiving iron supplementation also had a lower risk of sleep disorders.