neuro neutral

A two-word alternative I thought of not so long ago that can describe a character or a person's personality or mental state that became numb due to certain circumstances or experiences; or just a nonchalant person.

You know that guy used to be full of energy, but ever since that incident, he became neuro neutral.

I'm just neuro neutral when it comes to situations like these, because I don't want to get involved.

He's been starting to feel neuro neutral ever since that girl left a deep void in his heart.