Link between the immune system and schizophrenia

There has been mounting evidence that inflammation and the immune system play key roles in the development of schizophrenia and other psychiatric conditions.

Researchers from the UK Medical Research Council recently analysed microglia. These act like gardeners to our brain, weeding out any infection and ‘pruning’ unwanted connections between brain cells.

To record the activity of microglia, researchers injected 56 people with a chemical dye. The highest level of activity were found in those with schizophrenia and also those at high risk of developing schizophrenia.

“This is a real step forward in understanding.” says Dr Oliver Howes, head of psychiatric imaging group at the MRC Clinical Sciences Centre.

“For the first time we have evidence that there is over-activity even before full onset of the illness.”

He goes on to explain that if they were able to reduce this activity, they might be able to prevent the illness. He notes that this would need to be tested, but is a key implication of the research.

His theory is that the microglia becomes too good at its job, severing too many (or the wrong) connections, leaving the brain wired incorrectly.

“You can see how that would lead to patients making unusual connections between what is happening around them or mistaking thoughts as voices outside their head and causing the symptoms we see in the illness.”

Small trials which have already taken place suggest that, when given alongside traditional medications, an anti-inflammatory drug may help people.

Further trials are now needed to investigate anti-inflammatory drugs that target just the microglia, instead of those that have a wider effect on the body (such as ibuprofen).

Dr Howes says patients should not attempt to self-prescribe any drugs and that any changes or decisions regarding medication should be made with their doctor.