Descartes’ Nightmare: The Convergence of Mind and Matter, and the State of Psychosomatic Medicine
Japan, 1962 – In what sounds like a deleted scene from a late-era Kubrick movie, 13 high-school students are placed in a relaxed setting and told to shut their eyes. They're then brushed with what they are told are leaves from either the Japanese Wax or the Lacquer Tree, both cousins of poison ivy known to induce similar skin reactions, and to which the subjects were previously shown to be allergic. Though the leaves are not actually from a poisonous tree, all 13 students develop skin reactions involving itching, erythema (redness of the skin due to increased capillary blood flow), swelling, and blisters, known to doctor-types as contact dermatitis. The high-schoolers are later exposed to the actual poisonous vegetation but are told the leaves are harmless. 11 of 13 have no reaction.
This experiment is one of the better known early attempts by modern science to validate the psychosomatic influence of suggestion and patient perception in determining disease outcomes. While it only included a small number of participants, leaving open the possibility that the results were due to chance, these blotchy children nonetheless help support the idea that the human mind has significant influence over the fleshy matter in which it resides. This particular study has been used for years by Birkenstock-wearing, incense-burning opponents of Western Medicine (who often incorrectly cite "poison ivy" as the experimental foliage) to promote their agendas of healing through the mind, positive thinking, hypnosis, and other hippy-dippy crap rather than popping pills. But maybe these free thinking healers are on to something. There's a growing body of hard scientific evidence supporting the mind's ability to persuasively influence bodily function and illness which most certainly has pharmaceutical companies shaking in their brightly-colored dissolvable capsules.
Humans have been trying to characterize the relationship between body and mind for thousands of years. Plato's Theory of Forms suggests that the material objects around us are merely shadows, or abstractions of the real world, and that for our intellect to interact with such entities, it must be inherently non-physical. In the thirteenth century, Christian philosopher Thomas Aquinas suggested that while the soul can exist independently of the flesh, it must set up shop in a physical human body to become a true person. But the most well known early thinker on mind and matter was seventeenth century French philosopher, Rene Descartes. Often termed Cartesian Dualism, Descartes' claim is that the immaterial mind and the material body are two completely separate entities that somehow manage to interact and exert control over each other. But while the philosopher's dualist ideas still spawn intellectual discourse in classrooms across the world, his efforts as a biologist leave something to be desired. Descartes reasoned that Dualism was made feasible by the pineal gland, a tiny piece of tissue in the central brain where he claimed the soul was granted access to the body. But let's cut him some slack; without the benefits of modern science, how was he to know the pineal gland is simply a blob of endocrine tissue churning out melatonin, the hormone responsible for regulating circadian rhythms?
Years later, German physician Johann Christian August Heinroth (1773 - 1843) coined the term "psychosomatic" to describe his theory that the mind can incite both mental and physical illness. And in the late 19 th century, French internist and hypnotism-advocate Hippolyte Bernheim, developed his theory of Suggestion and Autosuggestion, outlining the psyche's influence over illness and resulting in what today is known as the placebo effect, perhaps the most widely appreciated example of mind over medicine.
The word "placebo" is Latin for "I will please," and has come to refer to a pharmacologically inert substance which produces actual therapeutic results. In the early-to-mid 1900s researchers began toying with the idea that administration of a dummy pill could produce a therapeutic response in a variety of disease states, often as strong as that seen with actual medications. Over the years, the utility of the placebo has been demonstrated in almost every medical field you can think of. For example, studies have shown placebo to be 56% as effective at relieving pain as morphine, while experts have estimated that up to 75% of the effectiveness of antidepressants is due to the placebo effect! Numerous psychological theories have been proposed to explain the magic of placebo, the most prominent being classical conditioning. Just as Pavlov's dogs salivated at the sound of a bell which they'd previously associated with food, over time us humans unconsciously associate the clinical environment (i.e., pills, doctors, hospitals, etc.) with improved health and symptom relief. Thus, some incompetent doc can walk in and feed us a handful of Smarties and, remarkably, our pain is relieved. Of course, the reverse is true for those with a vehement distrust of physicians, in which case exposure to the medical milieu can result in a "nocebo (Latin for ‘I will harm’) effect," or the development of untoward effects as a result of a seemingly harmless intervention.
Tied in with classical conditioning is the "expectancy theory," in which a patient's expectations of improvement are thought to influence clinical outcomes, and are often more powerful than the actual pharmacologic effects of a drug. It has been shown that the expectancy theory is at least partially due to our brain's own production of opioids called endorphins, which reduce pain by binding to the same receptor as morphine. Our pain-control pathways are linked with areas of the brain responsible for producing complex thought and emotion (the cortex and limbic system, respectively) and therefore can presumably be triggered by patient preconceptions. Administration of naloxone, a drug which blocks the effects of opioids, has actually been shown to inhibit the placebo response in patients with expectations of improvement.
But regardless of how it happens, there is overwhelming evidence that placebo works. Though it's now included as a treatment arm in just about every clinical drug trial, many researchers, both academic and pharmaceutical, seem to take placebo for granted, writing it off as a nuisance standing in the way of hard, scientific data and a tangible pill which can be pushed, prescribed and, most importantly, sold. Which is a shame, because while a sugar pill may not be quite as effective as an actual medication, lurking quietly in the corner of most trial graphs sits a bar representing all the patients in whom placebo was actually effective. Not to mention, placebo therapy is generally associated with a far lower incidence of side effects than actual medication…and it's a hell of lot cheaper too.
But I know what you're thinking: the moment a doctor hands his/her patient a prescription for a theoretical construct, the beneficial effects go out the window. A patient can't be aware of a placebo or it won't work. Which of course is true, but there's a small yet aggressive push in medicine for taking advantage of patient expectations when doling out treatments, particularly in difficult cases in which medications may not be enough. A recent article in Pain Practice suggests emphasizing to patients the benefits and extreme effectiveness of medications they're being prescribed, while justifying their recommendation by stating such an action is not a lie per se, but merely a way to enhance placebo response. And I see where they’re coming from, because what's the harm in a little psychological persuasion if it benefits the patient, right?!
In 1975, Dr. Robert Ader, a researcher from the University of Rochester, tried to set the record for the longest discipline title in academia. He coined the term “psychoneuroimmunology (PNI)” to represent an emerging field of research exploring the crossroads where psychiatry/psychology, neurology, and immunology (the study of the immune system) all coalesced. By conditioning rats to associate saccharine-laced water with Cytoxan, a chemotherapy agent which induces nausea and suppresses the immune system, Ader showed that eventually the water itself affected the rodent’s immune function. This was the first evidence that the nervous system could directly impact the immune system, in this case through taste sensation. Since that time, a huge body of research has emerged characterizing a complex bidirectional relationship between neurotransmitters, the immune system, and neuro-hormones (hormones derived from the brain), all of which interact with each other in an incestuous, neurobiological orgy to influence states of both health and disease.
A great deal of PNI research has focused on the effects of anxiety and stressful emotional states (i.e., sadness, anger, fear) on patient health. Both short- and long-term stressors such as doctor’s examinations, divorce, unemployment, and depression have all been associated with impaired immunity, resulting in higher rates of infection, decreased antibody production, impaired wound healing, and decreased numbers of white blood cells, our body’s main defense against foreign invaders.
While most of these PNI researchers have taken the pessimistic route, over the past few years a group of scientists have grown tired of all this forlorn and stressful exploration, instead characterizing the effects of positive mental states. Being “happy” has now been linked with numerous biological effects including decreases in the stress hormone cortisol, high levels of which are linked with diabetes and cardiovascular disease. Happiness also results in decreased levels of fibrinogen, a protein involved in blood clotting which can contribute to heart disease, increased immune function, and antibody production.
These findings should be good news to all of you self-helpers and daytime TV viewers out there, as they essentially provide sound biological explanations for previously-unsubstantiated adages like, “The power of positive thinking,” and all those heart-wrenching Oprah stories about how people survive cancer by maintaining a positive attitude. Research has now tied positive emotions with improved clinical outcomes in not only cancer, but also numerous chronic conditions like heart disease, HIV, and autoimmune disorders. And perhaps this is where religion comes into the psychosomatic picture.
Scientists have been arguing for years over the biological purpose of religion. Many purport that belief in God is simply a byproduct of evolution. That like many aspects of civilization (i.e., art, writing, bowling, etc), religious beliefs were not specifically naturally selected for, but merely emerged incidentally as a result of our complex brain function. But others, like Scott Atran, anthropologist at the National Center for Scientific Research in Paris, and subject of a recent New York Times article on the evolution of religious beliefs, argue that religion was a beneficial evolutionary adaptation, offering our species both survival and reproductive advantages. Maybe those who were religious were better assimilated into their communities and culture, and thus had more opportunity to develop personal relationships resulting in protection from harm and a higher likelihood of finding a mate and reproducing.
But perhaps religious belief was also naturally-selected for its health benefits, and not just advantages manifested through cultural and reproductive interaction. Studies conducted by a wide range of researchers including internists, psychiatrists, and behavioral scientists – in general, not the most religious bunch - have shown that those with strong religious beliefs have healthier immune systems than those like myself who stopped going to church in the 5th grade, favoring meditative time trying to beat Super Mario Brothers instead. Jesus freaks have been found to have far lower levels of an immune protein called IL-6 involved in numerous disease states, and increased levels of both helper and cytotoxic T-cells, two types of white blood cells. Hospital prayer sessions are associated with shorter hospital stays and illness duration, improved symptoms of depression and anxiety, and in some marvelous union of Darwinian dogma and modern medicine, greater success with in vitro fertilization. Researchers speculate that such findings are most likely due to the positive influence of psychological factors such as better coping skills and positive thinking on the immune system.
In his 1871 work, The Descent of Man, Charles Darwin wrote, “A belief in all pervading spiritual agencies seems to be universal.” Perhaps improved health is part of the reason why.
But where do we stand now, in 2007, in terms of psychosomatic medicine and the therapeutic utility of patient perception? And is any of this information of practical use? While albeit slowly, the importance of illness perception is finally breaking through the once-skeptical walls of modern medicine. More and more, physicians are using Illness Perception Questionnaires (IPQs) to assess correlations between patient beliefs and clinical outcomes. IPQs are a series of questions designed to pick a patient’s psyche to characterize their beliefs on the symptoms’ cause, duration, consequences, and perceived control as well as the emotional representations of the illness from which they suffer. Sample questions include, “How long will your illness continue?” and “How much will treatment help your illness?” and patients rate their responses on a scale from 0 to 10. Doctors are also considering patient perceptions using more abstract methods. A recent study was able to correlate patient drawings with degree of recovery after a heart attack. On a schematic diagram of the heart, patients were asked to draw the size of the damage they thought they’d sustained. The size of the damage drawn turned out to be a better predictor of functional recovery and future healthcare costs than did troponin-T levels, a protein released as result of damaged heart tissue, commonly used to assess cardiac damage. In other words, larger perceived heart damage correlated with pessimistic perceptions of disease, resulting in worse clinical outcomes.
Other work out of Denmark has shown that uncertainty about symptoms and patient emotional response to illness is an effective predictor of future healthcare costs and the development of chronic conditions. They postulate that if patients had a complete understanding of their illness and its ramifications, long-term outcomes would be improved. Since in today’s HMO era, most doctor visits only last long enough to dole out a few prescriptions for Viagra, painkillers, and a variety of antidepressants, this more informative approach would obviously require some serious healthcare reform. As would the rapid administration of diagnostic tests, another factor shown to prevent anxiety and negative illness beliefs from developing.
Associations between patient beliefs and emotional states, and measurable clinical consequences such as physical functionality, shorter illness duration, and overall improved subjective quality of life, have now been documented in a slew of diseases, including Huntington’s, diabetes, chronic kidney disease, and arthritis. And while we still don’t know exactly why a Japanese high school student can be rubbed with a harmless leaf, only to develop a nagging, itchy rash, we’re certainly making progress in elucidating the connection between mind and body. Somehow, through a complex cascade of firing neurons, brain-derived hormones, immune molecules, and God knows what else, our psyche manages to muster a great deal of physical influence. And while I won’t be trading in my prescription meds for a hefty dose of perceptual realignment anytime soon, it’s nice to know I have some control over this sack of bones, muscles, and organs I tote around with me everywhere I go.
References
Barak Y. 2006. The immune system and happiness. Autoimmun Rev. 5(8): 523-7. Epub March 21, 2006.
Ikemi Y, Nakagawa S. 1962. A psychosomatic study of contagious dermatitis. Kyoshu J Med Sc. 13: 335-52.
