Hypnosis for chronic pain management: How it works maybe?
Posted Oct 25 2009 11:02pm
There are plenty of people who look at me as if I’m stepping right into woowoo when I start to talk about hypnosis for managing chronic pain. I’m happy to say that science has provided some good evidence that not only does hypnosis have a neurophysiological basis, but it also has some good effect.
What exactly is hypnosis? Well, contrary to popular belief, it is NOT about a ‘hypnotist’ doing something to someone else – and most especially NOT about making people do things that they wouldn’t ordinarily consent to. This is the misconception that stage hypnotists perpetuate in an attempt to keep their mystique.
Hypnosis is ‘an induction followed by a suggestion (or set of suggestions)’ - now that has a lot of mystique, doesn’t it?! ‘The suggestions that follow the induction usually include ‘‘. . .suggestions for changes in subjective experience, alterations in perception, sensation, emotion, thought, or behavior” (Green JP, Barabasz AF, Barrett D, Montgomery GH. Forging ahead: the 2003 APA Division 30 definition of hypnosis. Int J Clin Exp Hypn 2005;53:259–64., cited in Jensen, in press).
I didn’t know it, but hypnosis has been used at least since the 1840’s (first documented evidence), but probably much, much earlier than this if we are to believe that trance and suggestion performed by various healers the world over are actually hypnosis.
Jensen’s paper suggests there are three reasons for the resurgence in popularity of hypnosis for pain management:
confirmation that chronic pain is influenced by the activity of supraspinal neurophysiological processes
similar evidence that neurophysiological processes associated with pain are influenced by hypnosis
empirical confirmation that hypnotic analgesia is effective for chronic pain management
In the first part of this paper, he reviews the evidence for chronic pain being influenced by supraspinal neurophysiological processes. To translate, this means activity above the level of the spinal cord (both descending and ascending) is implicated. As Jensen puts it ‘the experience of pain is directly associated with multiple integrative and interlocking neurophysiological mechanisms and sites, with supraspinal sites playing a key role.’
It’s not enough to look only at the peripheral nervous system to understand how humans perceive pain – we need to look above and beyond! The specific areas thought to be involved are the thalamus, the insula, the primary (S1) and secondary (S2) sensory cortices, the anterior cingulate cortex (ACC), and the prefrontal cortex. This means that treatments can be based on altering activity in many of these sites, including hypnosis which affects the cortex .
Incidentally, that site is a very good one if you’re interested in the science behind hypnosis ( Hypnosis and Suggestion )
Jensen then briefly looks at imaging evidence that hypnosis has a direct effect on activity in many of the CNS sites associated with pain perception. Studies have shown that when people are taken through a hypnotic induction, and asked to ‘imagine pain’, the cortical activity is quite different from those who are asked to simply ‘imagine pain’ without an induction. He goes on to say ‘Presumably, if hypnotic suggestions can produce pain and increases in pain-related cortical activity, they might also be able to produce pain relief and decreases in activity in these same brain areas.’ – and he goes on to cite a further study where exactly this effect was obtained. In that study, participants with chronic pain were asked to imagine their pain ‘low’, ‘medium’ and ‘high’ – one group under hypnosis, and the other simply asked to imagine. While both groups achieved changes in perceived pain, along with concurrent imaging results, those who had been using a hypnotic induction had a greater response.
What is interesting is that hypnotic suggestion was able to target different areas of the brain – in one study, participants were asked to ‘imagine themselves distant from the pain’, leading to a change in activity in the ACC (a part of the limbic system that is associated with emotional responding), without concurrent change to the S1 and S2 cortices, which process sensation but not necessarily the emotional response to sensation. The reverse activity was achieved when participants were asked to ‘imagine changes in pain intensity ‘.
Clinical trials have also been held to study the effect of hypnosis on clinical chronic pain. Four new studies have been carried out since 2006, giving a total of 17 RCT’s for hypnosis – these recent studies demonstrate that ‘hypnosis was either as effective or more effective than other active treatments, and more effective than no treatment or standard care.’
Jensen identifies an interesting finding from these studies – although over 2/3 of participants continued to use self-hypnosis, only around 22 – 40% of participants experienced ‘clinically meaningful pain reduction’ which is 30% reduction in pain. Now why would people carry on doing something that doesn’t reduce their pain? Maybe it is, as Jensen points out, that this is a skill that can be carried out to produce even a small reduction in pain for some people, and it’s available at any time, so it may simply increase a sense of control and reduce the feeling of being overwhelmed.
The final section of this paper looks at ways to enhance the hypnotic effect – perhaps through virtual reality (already used for some painful procedures), combining hypnosis with neuralbiofeedback, and perhaps teaching self hypnosis early in the ‘life’ of a chronic pain problem. Jensen remarks that ‘it is also possible that this treatment could buffer some of the negative long-term effects of pain on the CNS.’ when endorsing the idea of early commencement of hypnosis for chronic pain – he then describes how hypnosis is currently being used in the military, on the battlefield, to help with war injuries.
Caution now: hypnosis doesn’t work for everyone. Not everyone who can be hypnotised will feel effects of hypnotic analgesia, and many will only feel effects short-term. Despite this, it seems a promising area for people who have chronic pain. Some real benefits ensue: it’s something a person can do for him or herself, it’s free, it has no side effects once learned, and most importantly, it has no calories!