Future evaluation studies should allow for the fact that suggestion with or without hypnosis is a component of broader treatment interventions adapted to a wide range of symptoms and presentations.

The evidence base is dominated by case studies and series, with a paucity of randomized controlled trials. Suggestions are generally symptom-focused (designed to resolve a symptom) or exploratory (using methods such as revivification or age regression to explore experiences associated with symptom onset). Suggestion is typically applied within the context of other treatment approaches, such as cognitive-behavioral, rehabilitative, or psychodynamic therapy. In recent decades suggestion in hypnosis has been more widely applied to treating functional neurologic symptoms. However, the therapeutic application of suggestion in hypnosis to functional and other symptoms waned in the first half of the 20th century under the separate pressures of behaviorism and psychoanalysis. Nineteenth-century practitioners treated functional symptoms with induction of hypnosis per se imperative suggestions, or commands for specific effects 'medical clairvoyance' in hypnotic trance, in which patients diagnosed their own condition and predicted the time and manner of their recovery and suggestion without prior hypnosis, known as 'fascination' or 'psychotherapeutics.' Modern treatments largely involve different types of imperative suggestion with or without hypnosis. We consider the derivation of hypnosis from these practices not only to illustrate the range of suggestive processes, but also the consistency with which suggestion has been applied to the production and removal of dissociative and functional neurologic symptoms over many centuries. Before then, other forms of magnetism and ritual healing practices such as exorcism involved unintentionally suggestive verbal and nonverbal stimuli. Animal magnetism, the immediate precursor of hypnosis, arrived at a psychologic concept of suggestion along with other ideas and practices which were then incorporated into hypnosis. The recognition of suggestion as a psychologic process with therapeutic applications was closely linked to the derivation of hypnosis from earlier healing practices. Suggestion in this sense refers to an intentional communication of beliefs or ideas, whether verbally or nonverbally, to produce subjectively convincing changes in experience and behavior. Suggestion in hypnosis has been applied to the treatment of functional neurologic symptoms since the earliest descriptions of hypnosis in the 19th century.

Hypnosis therapy