I work with refugees, and many come with horrific stories of rape, kidnapping, imprisonment, torture. None of us at the clinic work full-time; we wouldn't last.
Vicarious traumatization is a term coined by McCann and Pearlman in 1990 to describe the psychological response of those who work with victims of trauma, including "long-term alteration in the therapist's own cognitive schemas, or beliefs, expectations and assumptions about self and others." And this from Wikipedia: "Its hallmark is disrupted spirituality, or a disruption in the trauma workers' perceived meaning and hope."
I've noticed lately that it's less the details of the trauma, and more the trajectory of the overarching patient story that affects me most. As per Kurt Vonnegut's graph below, good stories end with an upswing. It's the curves that angle downward, with no hint at even a modest recovery, that get me.