Shell shock, now known as PTSD, was a severe condition during WWI causing severe psychological trauma. Symptoms included tremors, nightmares, and deafness, sidelining up to 40% of British troops at the Battle of the Somme. Initially thought to be nerve injuries from bombardment, as introduced by Charles Myers in 1917, psychological factors were later recognised as key causes. This lack of recognition worsened soldiers' health, and some were shot for 'cowardice' when they could not fight