Final answer:
Soldiers of World War I experienced a post-traumatic stress disorder known as shell shock, which was caused by the traumatic experiences of trench warfare.
Step-by-step explanation:
The post-traumatic stress disorder that soldiers of World War I experienced was called shell shock. Shell shock was a term used to describe the psychological trauma that soldiers experienced as a result of the intense and prolonged exposure to the horrors of trench warfare, including constant artillery bombardment. Soldiers who suffered from shell shock could display a range of symptoms such as anxiety, insomnia, nightmares, flashbacks, and emotional numbness.
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