A new study has deepened understanding of how iron is stored in the brain in people with psychosis, including schizophrenia. The findings offer important clues about the biology of the condition and points towards potential new approaches to treatment.
Psychotic illnesses such as schizophrenia and bipolar disorder affect millions of people worldwide, yet current treatments do not work for everyone. Research, supported by the NIHR Biomedical Research Centre: Oxford Health, aimed to understand more about the biology of psychosis, particularly changes in the brain.
Iron plays an important role in the brain. It is needed to make dopamine, a chemical that helps regulate mood, motivation and thinking. Previous research has shown that dopamine activity is often too high in people with psychosis, but the reasons for this have not been clear.
The study brought together results from 27 previous MRI brain imaging studies, including data from 879 people with psychosis and 813 people without the condition.
Researchers found that people with psychosis had lower levels of iron in several deep brain regions, notably in the substantia nigra, an area of the brain which helps control dopamine activity.
The study also found higher levels of neuromelanin-related signals in this same region. Neuromelanin is a dark pigment that forms in brain cells as a by-product of dopamine activity and binds to iron.
Importantly, preclinical evidence suggests that low iron in this region of the brain may increase dopamine activity. This could help explain why dopamine is overactive in schizophrenia.
These findings are significant because they point to a new way of understanding psychosis. Rather than focusing only on dopamine, the study suggests that changes in how iron is stored and used in the brain may play a key role.
Paper co-author Robert McCutcheon, Associate Professor of Psychiatry at the University of Oxford, Oxford Health NHS Foundation Trust Honorary Consultant and NIHR Biomedical Research Centre: Oxford Health researcher commented:
“These findings suggest that iron storage in the brain is altered in psychosis. Understanding this could help us identify new treatment targets by linking iron biology to dopamine activity.
“More studies, particularly those following patients over time, are needed. However, the study provides an important step forward in understanding the underlying biology of schizophrenia”
The paper, titled ‘Gray Matter Iron and Neuromelanin in Psychosis: A Systematic Review and Meta-Analysis of MRI Studies’ was published recently in The American Journal of Psychiatry.
