(NPR) About 40 million people in the U.S. suffer from some form of anxiety disorder, according to the Anxiety and Depression Association of America. That is a staggering figure. In her book On Edge: A Journey Through Anxiety, published in May, Andrea Petersen, a health reporter at The Wall Street Journal, writes in vivid, memorable detail about what it's like to experience acute anxiety. Petersen recounts a time as a college student in 1989 when she was one day seized by a terrible set of physical symptoms. Her heart rate zoomed, her breathing went shallow, and her vision dimmed. None of it stopped when she got...