Research on how sleep helps us deal with trauma...
"Our memories, as it turns out, are highly dependent on what we forget.During the day, our brains are recording. At night, they switch to editing, cutting out extraneous details and consolidating the important ones. Without this editing phase, the brain would be crowded with so much junk that—like a hoarder looking for their social security card—it wouldn’t be able to find the important things necessary for survival. Forgetting also enables the brain to erase out-of-date and inaccurate facts so they can be replaced with updated information.