Dr. David Rosenberg of Wayne State’s Medical school recently found that an abnormal amount of the chemical glutamate in several regions of the brain was a factor in obsessive-compulsive disorder.
Rosenberg and a team of WSU researchers collaborated with the University of Michigan and University of Toronto Hospital for Sick Kids in Toronto in an independent study that was funded by the National Institute of Mental Health. Rosenberg was the principal investigator and all work was done at Wayne State.
The study involved examining children with OCD using magnetic resonance imaging (MRI) and a new type of MRI that allowed researchers to measure brain chemistry without surgery.
Rosenberg said that children were studied because there has been very little study involving them, even though at least 80 percent of all cases of OCD have their onset in childhood and adolescence.
“This condition is as common as asthma in childhood, but had been very understudied,” he said. “Six million Americans suffer from the illness and most cases have their onset in childhood.”
Glutamate, he said, is like the brain’s light switch; it regulates a lot of chemicals. He said the neurotransmitter serotonin, which calms anxiety, could be the light and glutamate turns serotonin and other chemicals on and off.
“It had never been studied or really, to our knowledge, considered, in OCD,” he said. “But more and more of our research suggested that this might underlie a lot of the pathology of OCD and may be a treatment response marker.”
In children with OCD, the amount of glutamate in certain brain regions varies, he said, in some areas there is too much and in others not enough.
Glutamate levels in certain brain regions not only distinguished children with OCD from healthy children, he said, but higher levels of glutamate before treatment in the caudate nucleus, which deals with learning and memory, predicted better response to treatment. Therefore, he said, the higher the glutamate level in the caudate, the better the patient responded, which meant that these abnormalities may be reversible.
Based on these findings, Rosenberg said new glutamate modulating agents are being tested for the first time in adults and children with OCD.
Phillip Easter, Rosenberg’s research coordinator, said that working on this project and working to identify specific indicators that can be used in the future to aid clinicians and practitioners to better identify and treat obsessive compulsive disorder has been an “extremely rewarding experience.”
“It’s been a fantastic learning environment because this type of approach in biomedical research, which may seem intuitive, is actually quite rare and not a common practice,” he said.
He said the hope is that identifying relevant biomarkers of obsessive-compulsive disorder, it can lead to the development of new treatments that can help the 40 to 60 percent of patients that don’t recover with standard serotonin-based treatment.
Easter also said that the collaboration of different scientific disciplines -- including psychiatry, psychology, neuroscience, neuro-imaging and genetics -- were important to Rosenberg’s work and had important implications for future research projects.
“This type of interdisciplinary cooperation is extremely productive and will be important in the future to further advance our understanding of a variety of psychiatric disorders,” he said.
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