The following is a table from Biological Psychology, by Rosenzweig, Breedlove and Lehman, reproduced by kind permission of the publishers, Sinauer. This is not a book about hypnosis and, indeed, hypnosis isn't mentioned anywhere else in its 650 academic pages so it's not in any sense a flag waver for the hypnotherapy profession.
It compares various types of pain relief intervention, and hypnosis is the only one with no negative comment.
|Placebo||May activate endorphin-mediated pain control system||Sometimes inhibited by opiate antagonists|
|Hypnosis||Alters brain's perception of pain||Control unaffected by opiate antagonists|
|Stress||Both opioid and non-opioid mechanisms||Clinically impractical and inappropriate|
|Cognitive (learning, coping strategies)||May activate endorphin-mediated pain control system||Limited usefulness in severe pain|
|Opiates||Bind to opioid receptors in peri-aqueductal gray and spinal cord||Severe side effects due to binding in other brain regions|
|Spinal Block||Drugs block pain signals in spinal cord||Avoids side effects of systematic administration|
|Anti-inflammatory drugs||Blocks prostaglandin and leukotriene synthesis at site of injury||Major side effects|
|Aspirin||Blocks prostaglandin synthesis at site of injury||Does not block leukotriene synthesis|
|TENS/Mechanical||Tactile or electrical stimulation of large fibres blocks or alters pain signal to brain||Segmental control; must be applied at site of pain|
|Acupuncture||Similar to TENS||Sometimes affected by opiate antagonists|
|Central gray||Electrical stimulation activates endorphin-mediated pain control systems, blocking pain signal in spinal cord||Control inhibited by opiate antagonists|
|Cut peripheral nerve cord||Create physical break in pain pathway||Considerable risk of failure or return of pain|
|Rhizotomy (cutting dorsal root)|