The frequency of the development of a posttraumatic stress disorder (PTSD) after a traumatic event depends, among other things, on the type of traumatic experience. Up to 50% of rape victims and war victims develop symptoms of PTSD. Among the victims of other violent crimes approximately 25% develop a posttraumatic stress disorder. Traffic accidents or severe illnesses such as heart attacks or cancer lead in about 15% of the patients to a PTSD. If left untreated, there is a strong tendency to chronicity.
In the overall population there is a likelihood of approximately 1-9% of developing a PTSD later in life, with women being affected about twice as often as men.