Mystical psychosis is a term coined by Arthur J. Deikman in the early 1970s to characterize first-person accounts of psychotic experiences that are strikingly similar to reports of mystical experiences. According to Deikman, and authors from a number of disciplines, psychotic experience need not be considered pathological, especially if consideration is given to the values and beliefs of the individual concerned. Deikman thought the mystical experience was brought about through a "deautomatization" or undoing of habitual psychological structures that organize, limit, select, and interpret perceptual stimuli. There may be several causes of deautomatization—exposure to severe stress, substance abuse or withdrawal, and mood disorders.
A first episode of mystical psychosis is often very frightening, confusing and distressing, particularly because it is an unfamiliar experience. For example, researchers have found that people experiencing paranormal and mystical phenomena report many of the symptoms of panic attacks.