In the 23 years since this book was first published, numerous books on the same lines have appeared. Techniques vary minimally, and very few discoveries or developments have been made in the field of using hypnosis in therapy. Such research as has appeared largely confirms what has been known for a very long time, such as its efficacy as an adjunct to chemical analgesia and anaesthesia for intrusive and painful surgical procedures. However, during that period a tremendous and astonishing amount of research has appeared in the fields of neurology, especially brain function, endocrinology and immunology and their interaction, or, more accurately, their total integration with psychological processes. While hypnotic techniques are much as they have been for so long, the underlying and mediating roles of these physical mechanisms in hypnosis are now substantially revealed. Understanding how hypnotic suggestions produce physical effects, and how these physical processes affect what is to be done in hypnosis will illuminate and guide what is attempted in hypnotherapy. The more the therapist bears these mechanisms in mind, the more effective and focused his work will be. This new edition therefore includes a summary account of the most cogent discoveries of the last two decades, and references to some of the most important knowledge acquired in this period in psycho-neuro-endocrino-immunology.