The experience of European soldiers and civilians was different from that of the Americans in that they had more cases of Post Traumatic Stress Disorder.
For 3 years before the United States joined the war, European soldiers had been fighting each other and European civilians had been caught up in the conflict.
They had therefore seen a lot of death and destruction which meant higher cases of PTSD compared to Americans who only experienced the First World War for a year.
Find out more on America's entry into WWI at https://brainly.com/question/11966689.