The likelihood of sustained symptoms of PTSD is higher if the rapist confined or restrained the person, if the person being raped believed the rapist would kill him or her, the person who was raped was very young or very old, and if the rapist was someone he or she knew.
The likelihood of sustained severe symptoms is also higher if people around the survivor ignore (or are ignorant of) the rape or blame the rape survivor.
There is evidence that susceptibility to PTSD is hereditary.
Approximately 30% of the variance in PTSD is caused from genetics alone.
Heightened startle responses and a smaller hippocampal volume have been identified as biomarkers for the risk of developing PTSD.
Recovery from posttraumatic stress disorder or other anxiety disorders may be hindered, or the condition worsened, by medication or substance use; resolving these problems can bring about improvement in an individual's mental health status and anxiety levels.
Quasi-experimental studies have demonstrated a relationship between intrusive thoughts and intentional control responses such that suppression increases the frequency of unwanted intrusive thoughts.
These results suggest that suppression of intrusive thoughts may be important in the development and maintenance of PTSD.PTSD causes biochemical changes in the brain and body, that differ from other psychiatric disorders such as major depression.Individuals diagnosed with PTSD respond more strongly to a dexamethasone suppression test than individuals diagnosed with clinical depression.Adults who were in foster care as children have a higher rate of PTSD, however as to the source of trauma, it is not clear whether the events that led to them going into foster care, i.e.:the death of a parent or events in foster care, i.e.:mistreatment or neglect, are the cause.Sexual assault in the military is a leading cause for female soldiers developing PTSD; a female soldier who is sexually assaulted while serving in the military is nine times more likely to develop PTSD than a female soldier who is not assaulted.While it is common to have symptoms after any traumatic event, these must persist to a sufficient degree (i.e., causing dysfunction in life or clinical levels of distress) for longer than one month after the trauma to be classified as PTSD (clinically significant dysfunction or distress for less than one month after the trauma may be acute stress disorder).