Iron imbalance in brain linked to mental illness

A Chinese research team from South China University of Technology in Guangzhou, Guangdong province, has published a review paper establishing links between disrupted brain iron metabolism and psychiatric disorders, including anxiety, depression and schizophrenia, offering a cross-disease framework for understanding how iron imbalances in the brain may drive the onset and progression of mental illness.

The research outcome presents a theoretical framework that charts the direction for subsequent mechanistic studies and clinical translation, said Wang Zhuo, an associate professor from SCUT's School of Medicine.

The paper, titled Iron Dyshomeostasis and its Neurobiological Mechanisms in Psychiatric Disorders, appeared in Molecular Psychiatry on August 29.

The work, led by Wang, synthesizes decades of existing research to propose that malfunctioning iron regulation — not just in the body, but specifically within the central nervous system — could be a shared biological thread across these conditions.

Iron is essential for many bodily functions, but its management inside the brain is exceptionally complex. For years, scientists have debated how iron levels relate to mental health.

"It is inappropriate to treat brain iron dyshomeostasis as a standalone disease," said Wang, adding that a more reasonable interpretation is abnormal brain iron status is prevalent across neuropsychiatric disorders, yet it remains scientifically unresolved whether such abnormalities act as a cause — risk or driving factor — or a consequence — secondary change induced by disease or medication.

By reconciling previously contradictory findings within a central-nervous-system-specific pathological framework, the study provides a road map for distinguishing causal effects from accompanying changes and advancing research on biomarkers and drug targets, Wang said.

The greatest value of it lies in elevating brain iron dyshomeostasis from a vague correlation to a verifiable and translatable cross-disease theoretical framework, while offering direction for resolving the fundamental question of cause versus effect, he said.

Wang's team took a novel approach: instead of examining each disease in isolation, they built a cross-disease model that considers environmental factors, genetic predisposition and neuroinflammation together.

Their analysis points to several core mechanisms through which iron imbalance may contribute to psychiatric illness. These include stress-induced changes to neural pathways, disruptions in the brain's iron distribution, the activation of cell-death pathways linked to iron — a process known as ferroptosis — and impaired iron transport along nerve fibers.

According to Wang, the work lays essential groundwork for further mechanistic studies, the pursuit of diagnostic biomarkers and the design of targeted intervention strategies. He added that the study breaks from conventional single-disease, single-mechanism approaches by "comprehensively incorporating multiple influencing factors, including environmental conditions, genetic characteristics and neuroinflammation".

However, the research team also acknowledged significant hurdles to translating this knowledge into clinical practice. Current therapeutic approaches struggle to cross the blood-brain barrier — the protective filter that shields the brain from many substances — and often lack the precision needed to target iron metabolism safely and effectively.

Wang further noted that future progress will require advances in real-time monitoring of iron metabolism changes, better spatial mapping of cerebral iron distribution and the development of specialized tools for research and clinical use.

Wang and Wu Zuqiang, a chief traditional Chinese medicine physician from the Sixth Affiliated Hospital of SCUT, are the co-corresponding authors of the paper.

Li Chuyue, an undergraduate student, and Tan Shuangyi, a postgraduate student, from SCUT serve as the co-first authors, while SCUT is the sole completing institution for the research.