People have post traumatic stress due to parental abuse, military combat and many other things. Memories associated with the trauma come into conscious attention when one perceives anything in the environment in which the traumatic event occurred. For example, if a combat veteran hears the sound of a car backfiring, it may trigger a memory of gunfire he heard when he was traumatized. Though there is no danger of being shot in the current situation, the sound of a car backfiring is similar to a gun being fired. This is called post-traumatic stress. One relives the hurtful, injurious moment over and over again.
One way to cope with PTSD is to attempt whenever possible to avoid situations and people that trigger the bad memories. Does moving away from a place that has many triggers then make sense? Well, yes it does. But a geographic change may not be enough. One must change something inside themselves. That is where the problem is. Avoidance sometimes makes sense. But approaching the problem at its root may necessary for the person to regain more or less of their mental competence. Feeling afraid of what is in your own mind is a great handicap to thinking and feeling. And, in turn, can degrade one’s ability to work and develop social relations.
But there are some people who were high functioning and mentally sound before their trauma occurred. For them, PTSD is less likely to occur than in others who had not been as healthy. Deep explorations into the mind such as EMDR and psychoanalytic treatment to rid the mind of trauma memories may not be necessary in such cases. So, for those who are mentally durable, a change in geography may be all they need.