Post Traumatic Stress Disorder, or PTSD, is a psychiatric disorder that can occur following the experience or witnessing of life-threatening events such as military combat, natural disasters, terrorist attacks, serious accidents, or violent personal assaults like rape. Most survivors return to usual given time.

However, some people have stress reactions that do not go away on their own and worsen over time. These individuals may develop PTSD. Those who suffer PTSD often re-live the experience through nightmares and flashbacks, have difficulty sleeping, and feel detached or estranged. These symptoms can be severe enough to significantly impair the person's daily life.