One East Tennessee man witnesses a deadly shooting by an attacker in a church.

Another East Tennessee man witnesses a deadly shooting by an attacker in an airport.

In the aftermath one decides to arm himself for personal safety. The other does his best to avoid any interaction with guns.

“Somebody that would avoid firearms or somebody that would arm themselves afterwards, these are both survival instincts. These are both the part of your brain that is trying to make you survive, control some future event and feel like you have control over it,” said Dr. John Kupfner, a psychiatrist and expert on Post Traumatic Stress Disorder.

“Post Traumatic Stress Disorder affects up to 10 percent of the population we all know people who have PTSD now or will later,” said Dr. Kupfner. He calls it a natural response in the animal part of our brain that can guide behavior. And in the great majority of cases, time is a great healer.

PART 1: Witness to a traumatic shooting: The decision to get guns

“Time is the best healer. It is also the slowest healer. Acceptance of what you’re going through is a huge part of treatment," he said.

"Understanding it doesn’t make you weak or not strong, and then being able to talk about it,” said Dr. Kupfner who adds “talk therapies” are the most important part of coping with PTSD.

PART 2: Witness to a traumatic shooting: The decision not to get guns

“Understanding, processing your triggers and reassuring yourself using coping skills” can help most people live a more “normal” life after they have experienced an unexpected traumatic event.

If you or a loved one is suffering from prolonged stress or fear after living through a life-threatening event such as a car crash, Dr. Kupfner recommends reaching out to your primary care doctor as “the first and best place to start” for guidance about counseling and treatment.