Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study

Abstract Despite observational studies linking brain iron levels to psychiatric disorders, the exact causal relationship remains poorly understood. This study aims to examine the relationship between iron levels in specific subcortical brain regions and the risk of psychiatric disorders. Utilizing t...

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Main Authors: Wei Du, Biqiu Tang, Senhao Liu, Wenjing Zhang, Su Lui
Format: Article
Language:English
Published: Nature Publishing Group 2025-01-01
Series:Translational Psychiatry
Online Access:https://doi.org/10.1038/s41398-025-03231-8
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author Wei Du
Biqiu Tang
Senhao Liu
Wenjing Zhang
Su Lui
author_facet Wei Du
Biqiu Tang
Senhao Liu
Wenjing Zhang
Su Lui
author_sort Wei Du
collection DOAJ
description Abstract Despite observational studies linking brain iron levels to psychiatric disorders, the exact causal relationship remains poorly understood. This study aims to examine the relationship between iron levels in specific subcortical brain regions and the risk of psychiatric disorders. Utilizing two-sample Mendelian randomization (MR) analysis, this study investigates the causal associations between iron level changes in 16 subcortical nuclei and eight major psychiatric disorders, including schizophrenia (SCZ), major depressive disorder (MDD), autism spectrum disorders (ASD), attention-deficit/hyperactivity disorder, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, and insomnia. The genetic instrumental variables linked to iron levels and psychiatric disorders were derived from the genome-wide association studies data of the UK Biobank Brain Imaging and Psychiatric Genomics Consortium. Bidirectional causal estimation was primarily obtained using the inverse variance weighting (IVW) method. Iron levels in the left substantia nigra showed a negative association with the risk of MDD (ORIVW = 0.94, 95% CI = 0.91–0.97, p < 0.001) and trends with risk of SCZ (ORIVW = 0.90, 95% CI = 0.82–0.98, p = 0.020). Conversely, iron levels in the left putamen were positively associated with the risk of ASD (ORIVW = 1.11, 95% CI = 1.04–1.19, p = 0.002). Additionally, several bidirectional trends were observed between subcortical iron levels and the risk for psychiatric disorders. Lower iron levels in the left substantia nigra may increase the risk of MDD, and potentially increase the risk of SCZ, indicating a potential shared pathogenic mechanism. Higher iron levels in the left putamen may lead to the development of ASD. The observed bidirectional trends between subcortical iron levels and psychiatric disorders, indicate the importance of the underlying biomechanical interactions between brain iron regulation and these disorders.
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spelling doaj-art-b5e2f25e13eb4840b703181e814daefe2025-01-26T12:53:41ZengNature Publishing GroupTranslational Psychiatry2158-31882025-01-0115111010.1038/s41398-025-03231-8Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization studyWei Du0Biqiu Tang1Senhao Liu2Wenjing Zhang3Su Lui4Department of Radiology, and Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan UniversityDepartment of Radiology, and Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan UniversityDepartment of Radiology, and Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan UniversityDepartment of Radiology, and Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan UniversityDepartment of Radiology, and Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan UniversityAbstract Despite observational studies linking brain iron levels to psychiatric disorders, the exact causal relationship remains poorly understood. This study aims to examine the relationship between iron levels in specific subcortical brain regions and the risk of psychiatric disorders. Utilizing two-sample Mendelian randomization (MR) analysis, this study investigates the causal associations between iron level changes in 16 subcortical nuclei and eight major psychiatric disorders, including schizophrenia (SCZ), major depressive disorder (MDD), autism spectrum disorders (ASD), attention-deficit/hyperactivity disorder, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, and insomnia. The genetic instrumental variables linked to iron levels and psychiatric disorders were derived from the genome-wide association studies data of the UK Biobank Brain Imaging and Psychiatric Genomics Consortium. Bidirectional causal estimation was primarily obtained using the inverse variance weighting (IVW) method. Iron levels in the left substantia nigra showed a negative association with the risk of MDD (ORIVW = 0.94, 95% CI = 0.91–0.97, p < 0.001) and trends with risk of SCZ (ORIVW = 0.90, 95% CI = 0.82–0.98, p = 0.020). Conversely, iron levels in the left putamen were positively associated with the risk of ASD (ORIVW = 1.11, 95% CI = 1.04–1.19, p = 0.002). Additionally, several bidirectional trends were observed between subcortical iron levels and the risk for psychiatric disorders. Lower iron levels in the left substantia nigra may increase the risk of MDD, and potentially increase the risk of SCZ, indicating a potential shared pathogenic mechanism. Higher iron levels in the left putamen may lead to the development of ASD. The observed bidirectional trends between subcortical iron levels and psychiatric disorders, indicate the importance of the underlying biomechanical interactions between brain iron regulation and these disorders.https://doi.org/10.1038/s41398-025-03231-8
spellingShingle Wei Du
Biqiu Tang
Senhao Liu
Wenjing Zhang
Su Lui
Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study
Translational Psychiatry
title Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study
title_full Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study
title_fullStr Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study
title_full_unstemmed Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study
title_short Causal associations between iron levels in subcortical brain regions and psychiatric disorders: a Mendelian randomization study
title_sort causal associations between iron levels in subcortical brain regions and psychiatric disorders a mendelian randomization study
url https://doi.org/10.1038/s41398-025-03231-8
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