Post-traumatic stress disorder (PTSD) can develop after a very stressful, frightening, or distressing event, or after a prolonged traumatic experience. Some of the events that can lead to PTSD include natural disasters, war, physical or sexual assault, abuse, accidents, and other serious events. However, not everyone who experiences a traumatic event develops PTSD, and many factors play a part. Some of the risk factors that may increase the likelihood of developing PTSD include:

• Exposure to previous traumatic experiences, particularly during childhood
• Getting hurt or seeing people hurt or killed
• Feeling horror, helplessness, or extreme fear
• Having little or no social support after the event
• Dealing with extra stress after the event, such as loss of a loved one, pain and injury, or loss of a job or home
• Having a personal or family history of mental illness or substance use

On the other hand, some resilience factors may reduce the likelihood of developing PTSD, such as seeking out support from friends, family, or support groups, and learning to feel okay with one’s actions in response to a traumatic event. Although its not clear exactly why people develop PTSD, a number of possible reasons have been suggested. One suggestion is that the symptoms of PTSD are the result of an instinctive mechanism intended to help you survive further traumatic experiences. Another possible reason is that changes in the hippocampus, a part of the brain responsible for memory and emotions, may be related to fear and anxiety, memory problems, and flashbacks. Additionally, there may be a genetic factor involved in PTSD, and having a parent with a mental health problem is thought to increase your chances of developing the condition.