JONESBORO, AR (KAIT)- The shooting at Fort Hood Wednesday left four people dead and 16 injured.
Fort Hood shooter, who was identified at Ivan Lopez, was being treated for post-traumatic stress disorder along with depression and anxiety.
According to the National Institute of Mental Health, PTSD impacts nearly 8 million Americans, which includes war veterans and anyone who experiences or witnesses a traumatic incident in their life.
"I don't always think if a person had PTSD they will always snap but it is a possibility," said Amy Flaherty, president of True Hope Counseling in Jonesboro. "And that snapping may look different for each person."
Flashbacks, bad dreams and frightening thoughts are just a few symptoms of post-traumatic stress disorder. Flaherty is a licensed psychological examiner and said she treats a client with PTSD or trauma about twice a month.
"PTSD does not just affect the person who has been in combat or in a trauma, it effects the whole family system," she said.
People who have PTSD may feel stressed or frightened even when they're no longer in danger. But there are warning signs to look for in adults.
"A change in their behavior, a change in their personality, increase in irritability, isolating themselves," Flaherty said.
The person will also experience nightmares and difficulty sleeping.
"If they have an increase startle response such as when a car backfires that they jump more than the normal person would," Flaherty told Region 8 News.
Fort Hood shooter Ivan Lopez had two deployments but was not directly involved in combat. Flaherty said just witnessing a traumatic event could lead to PTSD.
"It doesn't necessarily mean you have to have a gun in your hand but just being in a high stress environment for prolonged periods of time can trigger some PTSD symptoms," she said.
There are a number of treatments available.
"The most effective way is to really use a holistic method and that means I work with the person's physician, I work with the family as a whole," Flaherty explained. "In order for that person to really heal we need to address the whole family."
Flaherty said all veterans should undergo therapy once they return home from war.
"It is such a readjustment from the situation and the world of war into the civilian life," she said.
Flaherty also suggest veterans reach out to Veteran Affairs for other information and resources.