What is responsible for the placebo effect and hypnosis?
In the 1840s, a Scottish doctor living in India named James Esdaile was frequently visited by men with enormous tumours (weighing up to 45 kg) in the scrotum, caused by mosquito bites. The operation to remove them was so painful that men would often put it off for years, only having it as a last resort.
Esdaile had read about hypnotism (or mesmerism, as he referred to it) and decided to try the technique as a way of relaxing patients, so that they would agree to have the operation.
To his surprise, he found that not only did the patients feel relaxed, but they also didn't feel any pain during the operations. In other words, hypnosis had somehow acted as a powerful anaesthetic. Esdaile reported that, in some cases, there was no pain or injury after the operation either, and that the healing process was faster. As he wrote, “less constitutional disturbance has followed than under ordinary circumstances. There has not been a death among the cases operated on.”
Word began to spread about this amazing surgeon who could remove the massive tumours in 20 minutes without pain or after effects, and soon patients began to flock to Esdaile’s hospital near Calcutta. Esdaile began to use hypnotism in other procedures too, including eye surgery, the removal of tonsils, breast tumours, and childbirth. Esdaile was sure that it wasn’t a matter of his patients pretending (to themselves and/or to him) that they weren’t feeling any pain — he noted that, in addition to a lack of writhing and moaning, patients didn’t display physiological signs of pain such as changes to pulse rate and eye pupils.
At the time Esdaile was practising, mortality rates for operations were massive: a staggering 50% of patients died during or after them. But in 161 recorded cases of Esdaile’s operations, the mortality rate was only 5%. The reasons for this aren’t clear. Esdaile himself believed it was due to “vital mesmeric fluids” passing from him to the patient, which stimulated the healing process. However, it was probably related to reduced loss of blood, and perhaps an activation of the same self-healing abilities that occur with a placebo.
The Hypnotic State
The hypnotic state is still mysterious — there is no clear explanation of what happens when a person becomes hypnotised, or how the state is different from normal consciousness. But the essential aspect seems to be that, under hypnosis, the normal conscious self becomes immobilised. Normal conscious functions such as volition and control are taken over by the hypnotist. And with the conscious self in abeyance, the hypnotist appears to have direct access to the person’s subconscious mind.
Certainly, one of the most striking aspects of hypnosis is the powerful influence of the mind (via the hypnotist's suggestions) over the functioning of the body. Esdaile was by no means the only physician to use hypnosis, but from the mid-nineteenth century, the practice was superseded by the use of chemical anaesthetics. But there were still some areas of medicine where the practice continued — dentistry, in particular. At the turn of the 20th century, hypnosis was dentists’ main method of pain management, and it became almost universal for dentists during the First and Second World Wars, when chemical anaesthetics were scarce and facial trauma was common. Even now, some dentists still use hypnosis, especially in cases where a person’s medical history precludes the use of an anaesthetic.
Recent research with patients who had teeth extracted under hypnosis showed that “hypnotic-focused analgesia” can increase pain thresholds by up to 220%. (1) This research also found that 93% of patients experienced reduced postoperative pain and haemorrhage. (This links to Esdaile’s finding that mortality rates decreased very sharply as a result of his use of hypnosis. Hypnosis can reduce blood loss and haemorrhage.)
Beyond its analgesic properties, there is a great deal of evidence that hypnotism can have a powerful healing effect. During the early to mid-nineteenth century, the technique was used by physicians as a treatment and found to be effective against conditions such as epilepsy, neuralgia, and rheumatism. However, hypnosis appears to be particularly effective with skin conditions. In highly suggestible people, hypnosis has been used to rapidly heal wounds and burns, to make warts and blisters disappear and to control the bleeding of haemophiliacs. Conversely, highly suggestible people may produce blisters or burn marks, if they are told by a hypnotist that their skin has been burnt, or if they are blindfolded and the hypnotist pretends to touch them with a red hot poker or another object. (2)
Explaining Healing Under Hypnosis
Even though the effects of hypnosis are unexplained, it seems likely that the analgesic and healing properties of the state involve similar processes to the placebo effect. Research has made it very clear that the placebo effect isn't just about patients believing that their conditions have improved. Real physiological and neurological changes take place; genuine healing occurs. Recent research (most notably by Dr. Ted Kaptchuk at Harvard Medical School) has found that placebos can have a significant effect even when people know they are taking them.
Both the placebo effect and hypnosis suggest that we have a good deal more influence on our physiological functioning than we usually realise. Our beliefs and intentions seem to be able to activate innate self-regulating and even self-healing powers. A hypnotist simply creates the conditions under which these powers can be activated.
One of the most mysterious aspects is why we don't have access to these self-regulating powers in our normal conscious state. We can't simply say to ourselves, "Okay, 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 back pain." We can only use these abilities unconsciously, through the intervention of a doctor of a hypnotist.
For me though, perhaps the most important implication of the regulating and healing effects of hypnosis (and also the placebo effect) are what they suggest about the relationship between the mind and the body. In modern materialistic science, the mind is usually seen as a kind of "shadow" of the brain. Mental activity is a product of — and is equivalent to — brain activity. All mental states can be reduced to brain states.
However, if the mind is just an epiphenomenon of the brain, the powerful physiological effects of hypnosis and the placebo effect don't make any sense. How could an epiphenomenon bring about such powerful changes to the primary thing that it’s a byproduct of? How can a shadow change the object that it’s the shadow of? To use a different metaphor, it would be equivalent to suggesting that the images on the screen of a computer can change the software of the computer.
In other words, hypnosis and the placebo effect (and similar phenomena such as psychosomatic illness and psychogenesis, when mental intention generates illness) suggest that the mind is not just an epiphenomenon of the brain. In fact, since mental intentions (either our own or a hypnotist’s) can bring about such powerful changes to the body, it seems likely that mind is more fundamental than the material stuff of our bodies.
I believe that our culture urgently needs to adopt a "post-materialist" model of reality, which includes the principle that consciousness or mind are not byproducts but primary qualities of the world. One possibility is panpsychism, which suggests that consciousness is an intrinsic property of all material particles. Another is what I call "panspiritism" which suggests that the primary reality of the universe is a "fundamental consciousness" (or spirit) that pervades all space and all material forms.
Such post-materialist perspectives are the only hope of understanding rogue phenomena such as hypnotic healing and the placebo effect.
(1) Facco, E. et al. (2011) Effects of Hypnotic Focused Analgesia on Dental Pain Threshold. International Journal of Clinical & Experimental Hypnosis. 59 (4), 454–68.
(2) Kelly, E. F. et al. (2007). Irreducible Mind: Toward a Psychology for the 21st Century. Lanham, MD: Rowman & Littlefield.