I'd say it is pretty bleak, especially if you look at it at a wide angle...
Even one of the girls in the show (Sara) is sexually abused often, and even ends up becoming pregnant as a result of it.
I suppose it just depends on how we decide to function. Could our own will power save us, or would we break down as a result of our predicament?
Especially in how much we can control. In the anime Shu (after being captured) wasn't able to take control of the situation until after he became a soldier. And even then he endured punishment for what he believed in. Even we have our own breaking points, where we abandon our own morals etc. And yet Shu was able to overcome them (hardships not withstanding of course). However, is that the grace of entering in a new world? Being born into that kind of thing, only makes for an indoctrinated soldier it would seem.
Since everyone else is... I'll speculate myself.
I know that I have a strong will, and whilst it hasn't really been tested (not like I've been in an adverse situation) I know I'd go for the most proper outcome... Though perhaps unlike the show, my time would be short lived.

Like that if I decided to rise up against the commander or someone, that I would be immediately shot down by someone else. Though it would be bittersweet, that while I was unable to save anyone else, I had saved myself from having to experience this traumatic event.
That is another thing though... If you were a prisoner at a concentration camp during WWII, would you take the first chance to revolt? Even to the very end some prisoners obeyed the Nazis, some survived, and most did not. And as a result, living through that, they incurred the trauma and were able to come out of it... I wouldn't be surprised if most Prisoners contemplated suicide (during and after the ordeal). And nowadays, some of them, only have the idea of spreading their story, which has become important to them, so as not for the same mistake to occur again.
EDIT: I see it got moved XD that's okay, I too realized it was one of those teetering subjects... On the one hand we're talking about themes and life, and on the other, of an anime... (though I'm not sure if here will garner as much interest).