Neuromelanin-sensitive MRI (NM-MRI) can serve as a potential biomarker for psychosis, according to research published in the Proceedings of the National Academy of Science.
The imaging technique has proven reliable in detecting neuron loss in people with neurodegenerative illnesses, but now can serve as a marker of dopamine function in those without neurodegenerative disorders. NM-MRI also provides many advantages over conventional invasive methods or modalities requiring radiation exposure, such as PET, explained study author Guillermo Horga, MD, PhD, of Columbia University in New York, in a news release.
“The main advantages of this technique are that, compared to other established and more direct measures of dopamine function, neuromelanin-sensitive MRI does not involve radiation or invasive procedures,” Horga said. “This advantage makes it more suitable for pediatric populations and for repeated scanning, which could be useful to monitor the progression of illness or response to treatment—and it only takes a short scan that could be implemented in most clinical scanners.”
Neuromelanin is created within dopamine neurons of the midbrain, specifically in an area that operates reward and movement. It is produced over a long time period and only clears following the death of a cell, a phenomenon seen in neurodegenerative disorders like Parkinson’s disease.
As part of their research, the team conducted multiple tests to determine NM-MRI's effectiveness. One of those included examining the link between NM-MRI signal and the severity of psychosis. They found more severe symptoms were connected with higher NM-MRI signals in a specific brain pathway of patients with schizophrenia and in those at-risk for the disease.
Horga and colleagues now plan to expand their research further and establish NM-MRI as a more predictive tool.
“We are now extending this work to see if we can detect abnormalities in neuromelanin signal that help us predict which individuals are more likely to develop a psychotic disorder among those who already show early symptoms of psychosis,” Horga concluded. “We are also interested in exploring whether neuromelanin-sensitive MRI could be used in the future to determine who might best benefit from dopaminergic treatments.”
The study was funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health.