In “Psychology 9th Edition", David Meyer explained that whether a person gets PTSD (Post Traumatic Stress Disorder) after a traumatic event could probably of 4 reasons as the evidences proposed: 1. the greater the emotional distress during trauma; 2. the more frequent an assault experience; 3. a sensitive limbic system; and 4. genes.
However he had also stated that there were considerable disagreements over the diagnosis of PTSD. In real, the actual incident of PTSD is infrequent. It is also known that in some clinical settings, hypnotic skills were employed to lead the patients to revisit the experience. However, it is important for us to understand that "hypnotically refreshed" memories does combine fact with fictions. When an hypnotic skill is employed, it engaged people's ability to focus on certain images or behaviors, sometimes these experiences could be a suggested experience rather than true experience.
Pertaining to the issue of PTSD, evidence had also suggested that well intentioned attempts to have people relieve the trauma may exacerbate their emotions and pathologize normal stress reaction (Wakefield & Spitzer, 2002; Devilly et al., 2006; McNally et al., 2003; Rose et al., 2003).
Just some thoughts.....
Re: David G. Myers (2008). Psychology Ninth Edition. NY: Worth Publishers. Chapter 14, pg. 605