In World War One, thousands of troops began suffering from psychiatric disorders which were given the name 'shell shock'. It was initially thought that shell shock was caused by soldiers' proximity to exploding shells, but it soon became clear that the conflict was having an unprecedented psychological impact. Alex Last presents BBC archive recordings of WW1 veterans talking about their experiences.
Photo: French soldiers taking cover during a German bombardment, 1918 (Photo by General Photographic Agency/Getty Images)