What is the term for the condition in which someone is mentally fragile due to explosion?

Solution 1:

It's considered "ill-defined", but the term shell shock is often used for what you're describing. However, I would caution against using this in most situations.

Shell shock was a term used in the World War I era, but it was poorly understood at the time. In the World War II era, diagnoses of shell shock were replaced with diagnoses of combat stress reaction, which is often associated (but not the same as) PTSD. This quote from the Wikipedia page on CSR (linked above) emphasizes the difference:

Combat stress reaction is generally short-term and should not be confused with acute stress disorder, post-traumatic stress disorder, or other long-term disorders attributable to combat stress, although any of these may commence as a combat stress reaction.

As to why I caution against using the term, it's not just that it's outdated and was vague at the time it was used - it's also considered somewhat offensive, from what I've heard, as it's disrespectful towards people actually suffering from CSR and PTSD. It is, however, still in our vernacular - a major security vulnerability was named after it in 2014, and when I was searching for the term on google, autocomplete recommended some game on Steam that I won't link because they don't deserve advertising. I also found an article about a politician being 'shellshocked' at public reaction to something he did.

I would strongly encourage you to check up on the Wikipedia pages for the terms (linked above) for further reading.

Solution 2:

The modern name for the condition is Post Traumatic Stress Disorder, and it can apply to civilians as well as soldiers.