Kids experience PTSD. Too often instead of recognizing PTSD children are labeled over sensitive, trouble makers, or other acting out behaviors. I came across a sheet of tips for parents and teachers about PTSD in children. Many of the suggestions work for adults too.
Update: Be careful following some of the links. I discovered that at least one of the links on the web page is hijacked to another site. The information is good but the links are old or not working. Search carefully.