How did trench warfare and the new weapons contribute to the numerous cases of shell shock

Trench warfare, combat in which armies attack, counterattack, and defend from relatively permanent systems of trenches dug into the ground. Trench warfare is resorted to when the superior firepower of the defense compels the opposing forces to ‘dig in,’ sacrificing their mobility in order to gain protection.

Explanation:

not to sure sdi, strategic defense initiative