Any of these memories may happen by themselves, or with other sense memories that were recorded from the same incident. These memories are known to often return as nightmares. Visual memories lend themselves to easily being able to identify the trauma from which they were recorded. In many cases, people think they are going crazy because reality is so different from their feelings. The symptoms people experience when this memory recall occurs, and the emotions and fallout that come with it, are what lead to a diagnosis of Post Trauma Stress Disorder.
Some therapists refer to it as a trauma to the psyche, comparing it to a physical trauma.
Recent research has shown that PTSD may actually be a physical trauma to the brain and nervous system. Marriage and relationship problems are a very common occurrence for people with this disorder. The good news is Post Trauma Stress Disorder is preventable in some cases, and treatable. Some people, especially attorneys and the news media, try to paint a picture of a bunch of violent cops beating up helpless innocent people. My experience, in the 1990's, has been that officers who are heavy handed on a regular basis are easily identified and readily dealt with by their peers, and eventually management.