INTERVIEW: Have images of 9-11 triggered anxiety in you?

This week we have been bombarded with video footage and memories of the 9-11 terror attacks on the World Trade Centre in New York and the Pentagon in Washington. For those of us who reported on it at the time, it remains a defining moment in our lives - we will never forget it. And for many people around the world, as they watch the Twin Towers crumble and the almost incredible change in the world as a result, it is understandably something that is seared in their memories. And for many people, not just in America but around the world, those recurring images will have brought back unwelcome thought and concerns. They can trigger post-traumatic stress disorder or PTSD symptoms or general anxiety for many people. Dr Jaryd Hiser is a psychologist at The Ohio State University Wexner Medical Center and he explains what the stress reaction warning signs are that we should watch for, and shares coping tips and when to seek professional help.