In India during the 1840s, a Scottish doctor named James Esdaile was frequently visited by men suffering from enormous tumours in the scrotum, caused by mosquito bites. The operation to remove the tumours was so painful that men would often postpone it for years.
Esdaile had learned about hypnotism (or mesmerism, as it was usually referred to then) and decided to try the technique as a way of relaxing patients in collaboration with local Hindu and Muslim mesmerisers. To his surprise, he found that not only did the patients feel relaxed, but they also felt no pain during operations. Esdaile also noted that patients didn’t seem to display physiological signs of pain, such as changes to pulse rate and pupil size.
Since then, evidence has accumulated showing that hypnosis can have an analgesic effect. A 2020 meta-analysis of 45 trials of the use of hypnosis for clinical pain found that 73 percent of hypnotised people experienced less pain than control groups (who didn’t have any pain interventions).
Research over the past 20 years at the Integrative Medicine Program at the University of Texas MD Anderson Cancer Center has found that patients who received a combination of a local anaesthetic and hypnotherapy (as opposed to a general anaesthetic) required less pain medication and reported less post-operative pain, as well as less nausea, discomfort, and fatigue.
The intensity of these effects depends on how susceptible a person is to hypnosis. Naturally, the analgesic and healing effects are strongest with people who are highly susceptible to hypnosis, and weakest with people with low (or no) susceptibility. However, research suggests that around three-quarters of people are susceptible to hypnosis to some degree (with around 10 percent highly susceptible), and so will potentially experience some benefits.
Recent research has also shown that hypnosis has efficacy with conditions such as irritable bowel syndrome (IBS), migraines, menopausal symptoms, and autoimmune disorders. In particular, hypnosis is effective with skin conditions, such as eczema and psoriasis, although scientists are unsure why this is. In highly suggestible people, it has been used to rapidly heal wounds and burns, and even make warts and blisters disappear.
The hypnotic state
It still isn’t entirely clear what happens when a person is hypnotised, or how the state is different from normal consciousness. Hypnotists attempt to induce a state of “relaxed focus” in which clients lose awareness of their surroundings and become open to suggestion. It’s almost as if a person’s normal conscious mind becomes inactive (or at least less active), which allows the hypnotist access to their subconscious mind.
One way of trying to understand how hypnosis works is to look at what differentiates people who are highly susceptible from those who are not susceptible. Research has shown that high susceptibility is linked to traits such as openness to experience, vivid imagination, and a strong capacity for both absorption and dissociation. A trusting attitude and a lack of anxiety are also important.
The neurological basis of hypnotism is rather unclear. One 2017 meta-analysis of neuroimaging studies of hypnosis concluded that “there remains little consensus concerning the neural mechanisms and a great deal of inconsistency.”
Hypnosis and the placebo effect
Given that we don’t fully understand how hypnosis itself works, we shouldn’t expect to fully explain its analgesic and healing effects either. However, they likely involve similar processes to the placebo effect, which shows that beliefs and mental intention can cause significant physiological changes.
Even though placebo pills contain only inert substances (like rice powder or sugar), if we believe that the treatment is real, there is a good chance that we will experience healing. Research has found that placebos can have a significant effect even when people know they are taking them.
Neuroimaging has confirmed the placebo effect. In a 2021 study, patients who were given placebos for pain relief showed decreased activity in the periaqueductal grey region (which helps the body to suppress pain).
The placebo effect demonstrates that our minds have some influence over our physiological functioning. It suggests that we possess some capacity for self-healing, which is activated by placebos. And I would suggest that hypnosis works in the same way.
One of the strange aspects of this is why we don’t have access to these self-regulating powers in our normal conscious state. We can’t simply say to ourselves, “OK, I’m going to make myself numb to pain” or “I’m going to use my mind’s power over the body to improve the symptoms of my rheumatism or my migraine.” We can only use these abilities unconsciously, if at all.
Perhaps this is because we are accustomed to thinking of ourselves in mechanical terms. Sometimes we think of our bodies as separate from our minds, as vehicles that we live inside, which are not really “us.” It could be that this attitude prevents us from consciously using these self-regulating abilities.
However, as I suggest in my book Spiritual Science, perhaps the most important implication of the regulating and healing effects of hypnosis (and also of the placebo effect) is that they suggest that the mind is not just a by-product of the brain.
If it were, the powerful physiological effects of hypnosis and the placebo effect wouldn’t make sense. How can a shadow change the object that it’s the shadow of? It would be equivalent to suggesting that the images on the screen of a computer can change the software of the computer.
Perhaps we should think of the mind as something more than just brain activity. After all, many scientists and philosophers are beginning to think of consciousness in a similar way. Approaches that suggest that consciousness is fundamental or universal, and can’t be reduced to physical properties, are growing in popularity and would certainly make it easier to explain the strange healing effects of hypnosis.