Inflammation in the brain is linked to a greater risk of schizophrenia, according to a new study published in the American Journal of Psychiatry. The research is the first to show that immune cells are more active in the brains of people diagnosed with schizophrenia as well as those who are at risk for the disease.
“Schizophrenia, like other mental health disorders, is a complex disease that we know is caused by an interplay of genetic, behavioral, and other contributing factors,” said Professor Hugh Perry, chair of the Neuroscience and Mental Health Board at the U.K.’s Medical Research Council (MRC).
“This study adds to a growing body of research that inflammation in the brain could be one of the factors contributing to a range of disorders — including Alzheimer’s, schizophrenia, and depression — and with this new knowledge comes the hope of life-changing treatments.”
For the study, researchers from the MRC’s Clinical Sciences Centre and King’s College London used positron emission tomography (PET) scans to measure levels of activity of immune cells in the brain.
These cells, called microglia, respond to damage and infection in the brain, and are also responsible for rearranging the connections between brain cells so that they work as well as possible, a process known as pruning.
The researchers tested 56 participants, including those already diagnosed with schizophrenia, those at risk of the disease and those with no symptoms or risk of the disorder.
The findings showed that the activity levels of microglia in the brain increased according to the severity of symptoms in people with schizophrenia and that people with diagnosed schizophrenia had high levels of activity of these immune cells in their brain.
“Our findings are particularly exciting because it was previously unknown whether these cells become active before or after onset of the disease,” said Peter Bloomfield, doctoral student and lead author of the study at the MRC Clinical Sciences Centre. “Now we have shown this early involvement, mechanisms of the disease and new medications can hopefully be uncovered.”
The novel findings could completely change our understanding of schizophrenia, raising the possibility that offering early testing for people most at risk for the disorder could essentially catch the disease before it starts and help these individuals avoid the most severe symptoms.
“Schizophrenia is a potentially devastating disorder and we desperately need new treatments to help sufferers, and ultimately to prevent it,” said Dr. Oliver Howes, head of the psychiatric imaging group at the MRC Clinical Sciences Centre.
“This is a promising study as it suggests that inflammation may lead to schizophrenia and other psychotic disorders. We now aim to test whether anti-inflammatory treatments can target these. This could lead to new treatments or even prevention of the disorders altogether.”