This finding could "completely change our current understanding of schizophrenia" as it raises the possibility that testing people most at risk of the disorder ahead of time could allow them to be treated early enough to avoid its most severe symptoms, according to the Medical Research Council’s (MRC) Clinical Sciences Centre, based at Imperial College London.
The report’s lead author, Peter Bloomfield, said: "Our findings are particularly exciting because it was previously unknown whether these cells become active before or after onset of the disease. Now we have shown this early involvement, mechanisms of the disease and new medications can hopefully be uncovered."
The team tested a group of 56 people including those already diagnosed with schizophrenia, those at risk of developing it and those with no symptoms or risk of the condition. For the tests, they used positron emission tomography (PET) scans to measure levels of activity of immune cells in the brain.
These cells, known as 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. They found that 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.
Dr Oliver Howes, head of the psychiatric imaging group at the MRC Clinical Sciences Centre, added: “Schizophrenia is a potentially devastating disorder and we desperately need new treatments to help sufferers, and ultimately to prevent it.
“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.”
The research was funded by the MRC and King’s College London.