I'm only speaking from personal experience here. It's very difficult to screen somebody beforehand. I've found that sometimes you can get the best qualities in soldiers who have had previous trauma in their lives: they have been resilient and they've learned coping skills that will make them terrific soldiers. But then just a few more traumas can drive them over the edge, and their thinking is so distorted and rigid that they can't get better—but they're very good soldiers. Then again, it's also difficult because you could have somebody with a very average upbringing, and unfortunately so many things happen and they don't cope well.
It's difficult to pre-screen. I think there are some things they can look at, but it's difficult to say “yes” to one person and “no” to another. Does that answer your question?