1 in 4 people experience mental illness at some point each year and depression now affects a staggering 350 million people worldwide. Understanding the causes of depression is crucial if we’re to find ways of treating it effectively. And more and more research is suggesting that we look beyond our brains and into the immune system to find answers. We speak to Carmine Pariante, Professor of Biological Psychiatry at Kings College London, who’s been piecing together evidence on the role of our immune system in depression for 20 years. 

He explains why this research is considered by scientists to be "one of the strongest discoveries in psychiatry for the last 20 years", how it could revolutionise treatments and diagnosis and exactly why we think the immune system is causing changes in mood.

This episode is brought to you by MQ: Transforming Mental Health, the new major mental health research charity. Find out more about MQ’s work here: https://www.mqmentalhealth.org