According to Dr. Jeffrey A. Lieberman, psychiatrist-in-chief at New York Presbyterian Hospital-Columbia University Medical Center, witnesses to the Colorado massacre may begin to experience post-traumatic stress disorder (PTSD).

The event occurred during a theatrical viewing of the new Batman movie “The Dark Knight Rises,” and people present stated that a lone gunman let off smoke bombs and stalked his victims in the aisles; eventually killing at least 12 people and wounding 56 more. When you combine the shock of the event and the magnitude of the shooting, Lieberman believes that this is enough to trigger PTSD.

“On the emotional Richter scale it was very high,” he said. “You go to a movie like Batman because it’s fun-loving entertainment, and you are seeing kids in costumes and the last thought you are thinking about is some type of seriously dangerous, potentially life-threatening situation. The contrast adds to the potential for emotional trauma.”

Other psychiatric experts have said that it’s hard to know who would develop PTSD after an event like this since everyone’s tolerance for stress is different. Only about 7 to 8 percent of everyone present during the shooting will actually develop PTSD after such an event.

“Your individual vulnerability and resilience is determined by your genetic makeup, and also in part by the psychological features you have developed over the course of your lifetime — were you confident and successful and could you overcome experiences, or were you cautious and fearful?” said Lieberman.

Should people start suffering from PTSD, there are many different treatments for the condition. Some of those treatments can include antidepressants like Paxil and Effexor. Both medications have been known to cause serious side effects, which can include violent and suicidal thoughts and behavior and birth defects (PPHN, cleft palate and heart, lung and brain defects) in babies whose mothers take the drugs while pregnant.