How is PTSD represented in A Gesture Life novel?

This story does the interesting thing of showing Doc's point-of-view as a whirlwind of interconnected and tangential flashbacks, some about his life in America, some about his time in Japan, but all of them are intermingled, and a continuous dread runs through all of them, even though Doc is consistently pursuing a more peaceful life. As the novel goes on, we learn that this sporadic point of view is because he is constantly avoiding his traumatic memories about K, a rejected daughter who was sold to the army by her parents to be raped. Doc watched a terrible fate befall her, leaving him with PTSD, explaining the scattered point of view.