Posttraumatic stress disorder (PTSD)[note is a mental disorder that can develop after a person is exposed to a traumatic event, such as sexual assault, warfare, traffic collisions, or other threats on a person’s life. Symptoms may include disturbing thoughts, feelings, or dreams related to the events, mental or physical distress to trauma-related cues, attempts to avoid trauma-related cues, alterations in how a person thinks and feels, and an increase in the fight-or-flight response. These symptoms last for more than a month after the event. Young children are less likely to show distress, but instead may express their memories through play. A person with PTSD is at a higher risk for suicide and intentional self-harm.

Most people who experience a traumatic event do not develop PTSD. People who experience interpersonal trauma (for example rape or child abuse) are more likely to develop PTSD, as compared to people who experience non-assault based trauma, such as accidents and natural disasters. About half of people develop PTSD following rape. Children are less likely than adults to develop PTSD after trauma, especially if they are under 10 years of age.Diagnosis is based on the presence of specific symptoms following a traumatic event.