Narrator: This is Science Today. A national, randomized survey taken shortly after the terrorist attacks on September 11th revealed that almost half of those polled experienced extreme stress over the event - even though they had no direct relationship to the victims or the sites involved. Dr. Frank Schoenfeld, a clinical psychiatrist at the University of California, San Francisco, says this study also suggested that some people might be at risk of developing post traumatic stress disorder from excessive viewing of the attacks on television.
Schoenfeld: Judging from some of the earlier studies, there will be some people that will have been affected to the point where they might require medical attention just on the basis of this viewing.
Narrator: Schoenfeld says symptoms of post traumatic stress disorder include feelings of anxiety or intrusive thoughts about the traumatic event.
Schoenfeld: When something has human malicious intent, it's weighted very heavily towards producing a much more powerful psychological reaction in us than something that's more neutral - even if it's very destructive.Narrator: For Science Today, I'm Larissa Branin.