Anxiety
The philosopher Søren Kierkegaard, in "The Concept of Anxiety" (1844), described anxiety or dread associated with the "dizziness of freedom" and suggested the possibility for positive resolution of anxiety through the self-conscious exercise of responsibility and choosing. In "Art and Artist" (1932), the psychologist Otto Rank wrote that the psychological trauma of birth was the pre-eminent human symbol of existential anxiety and encompasses the creative person's simultaneous fear of – and desire for – separation, individuation, and differentiation.
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.