Each modern war seems to have its own version of combat stress. Today, PTSD is a serious issues that many soldiers and veterans face. However, in WWI, soldiers were diagnosed with a unique form of combat stress called shellshock. British scientific understanding of shellshock was fragmented and unstandardized. This paper examines the different understandings and treatments of shellshock and argues that the soldiers' perception of shellshock was highly influenced by psychologists and the scientific understanding of the time