Brain Inflammation in People at High Risk for Schizophrenia
Microglial activity in the brains of people who are healthy, people at high risk for schizophrenia, and people who have been diagnosed with schizophrenia.
A 2016 study by Peter S. Bloomfield and colleagues in the American Journal of Psychiatry used PET scans to compare the activity of microglia, immune cells in the central nervous system, in healthy controls, people with schizophrenia, and those at high risk for the illness. It found that both people with schizophrenia and those at high risk had greater brain inflammation than the healthy controls.
The study was the first to show that microglial activity was elevated in people at high risk (who showed some preliminary symptoms of schizophrenia). The finding had a large effect size.
Microglial activity was also correlated with symptom severity in the high-risk participants. Increased microglial activity was not linked to depression, suggesting that it is specific to the development of psychosis.
These findings resemble those of other recent studies showing increased inflammation in people at high risk for psychosis.
The study suggests that increased microglial activity occurs before a first episode of psychosis. That means it could help identify people who may develop schizophrenia. The findings also suggest that anti-inflammatory treatment could theoretically be used to prevent psychosis.
