The Concept of Anxiety
All of Kierkegaard's books have either a preface, dedication, or prayer at the beginning. This book includes a lengthy introduction. "The Concept of Anxiety" was published on exactly the same date as "Prefaces", June 17, 1844. Both books deal with Hegel’s idea of mediation. Mediation is a common thread throughout Kierkegaard’s works. His work up to this point was to show that faith was being mediated by knowledge. Here he takes up the questions of sin and guilt.
Anxiety sensitivity
In 1984 Steven Reiss wrote the 16 items on the brief questionnaire he called and copyrighted as the "Anxiety Sensitivity Index" (ASI). In 1986 Reiss, Peterson, Gursky, & McNally published the ASI questionnaire along with initial validity evidence. As of July, 2013, the ASI has been used in more than 1,600 research studies. As was predicted by Reiss and McNally (1985), a high score on the ASI is a powerful and unique predictor of who will have panic attacks, post-traumatic stress, and ordinary fears or phobias.