One group of people with schizophrenia seems to have too much of something called “glutamate” in a part of their brain called the frontal cortex. This group doesn’t respond well to the usual first set of medicines psychiatrists usually give them, which act through another chemical called dopamine.
If we can figure out who these patients are early on, we might be able to avoid trials of medicines that may not help them much. Instead, we could give them different treatments that might work better – especially clozapine, one of the underused treatments with the potential to benefit this group.
To find out who these patients are, Lejia Fan, a visiting graduate student from the Second Xiangya Hospital of Central South University, Changsha, China used a special kind of scan called “magnetic resonance spectroscopy” (1H-MRS). This scan can measure how much glutamate is in a person’s brain. Lejia set out to see if there was a clear link between having too much glutamate in a specific part of the brain and not responding well to a common antipsychotic (risperidone) for schizophrenia. She also tested if taking risperidone would make the glutamate problem worse for those who didn’t respond well. She studied 42 patients who were starting treatment for schizophrenia. The clinical team at Changsha followed the patients for three months to see how they responded.
What we found on this dataset was very interesting. The patients who didn’t respond well to the medicine had higher levels of glutamate in their brains compared to those who did respond. Even though the patients who didn’t respond well had higher levels of glutamate, risperidone didn’t seem to make the problem worse over the three months that patients were taking it.
So, what does this mean? It suggests that giving first-line antipsychotics without knowing if they’ll work might not help some people with schizophrenia. But, at least for the three months after starting risperidone, it didn’t seem to make the glutamate problem worse.
This study shows that there’s still a lot we need to learn about schizophrenia and how to treat it best. In the future, we need to do more studies over longer periods to see if finding out about glutamate levels can help us give better treatments to people with schizophrenia.