The Placebo Effect - A Matter of Belief

You have certainly heard of the placebo effect and you may have thought that a placebo only works because the person receiving it (medicine, a lotion or potion) doesn't know it's a placebo. It actually works because of belief.

As a person involved in the design and development of medical technology I now try to incorporate knowledge of belief and expectancy into many aspects of what we do. The "look and feel" of products, the attitude and beliefs of the prescriber and many subtle influences need to stack up for the benefit of the patient. A product needs to function - and it will be more effective if it can leverage patient belief.

Back in 1931 researchers had long recognised that the placebo effect was a useful conceptual model to better understand the safety and efficacy of medicines in development. It had been known for decades that some patients would say that they felt better just with the suggestion that they were being given a remedy. Back then, researchers interested in measuring the effects of a drug called sanocrysin on patients with tuberculosis, wanted to discount this observable placebo effect. Their idea was to give some patients a glass of distilled water whilst telling them they were really receiving sanocrysin. Ever since, placebo-controlled, double-blind studies have been deployed as a way of evaluating drugs in clinical trials. Consequently science has an awful lot of information on placebos - probably more than we have on all drugs put together.

In his book "Time for a Change", Richard Bandler describes (tongue in cheek) how he and a graduate student had planned to market placebo pills to the general public. They made plans to publish a leaflet with an index. A person would look up "Headaches" for example and read,

"When tested against other drugs, placebos work five out of six times - and no side effects."

Then it would say
"Take seven when you have a headache."

Unfortunately, the FDA complained that the effects would wear off and that the placebo would lose its efficacy. Bandler says that he knew that this could happen because some people would not have strong enough beliefs first time around. So they revealed their back-up plan.

"New! Placebo Plus! Twice the inert ingredients! Twice as powerful as before."

Nevertheless, the FDA wouldn't let them offer their capsules and told them it would be illegal and couldn't work. Bandler's view was "We had proved it would work. After all, we had decades of their own experimental results directly from them."

If the basis of placebo is belief, we can recognise that we must have learned or adopted beliefs in some way and therefore we can change them. Belief's are nothing to do with fact and are a construct of an individual or a group of individuals. Bandler says,

"My clients often knew a placebo when they got one. They still do. I actually give them the ability to believe that it works because it is a placebo. I explain that because they already know it works for a placebo, it will work forever. It does."

We can distinguish between placebo and placebo effect. Basically, any sort of treatment can act as a placebo but what determines if there is a placebo effect is the actual response of the patient to the intervention.

Based on the Latin for "I shall please," placebo takes many forms but has been offered as a sugar pill, a saline injection and distilled water. We have also seen placebo surgeries where patients are anesthetised, cut open and stitched up again to appear as if they have had surgical interventions even when they haven't. We have often heard sceptics dismiss responses to complementary and alternative therapies as "merely" placebo effects. However, whether in the past you have considered the effect a scientific annoyance or a miracle, its power is becoming much harder to deny as we shall see.

One of the most enduring questions about the placebo effect is whether this is an effect of human physiology or of psychology; is it of the mind or of the body? To me even if it "is in the mind" that was pretty impressive. Research is now demonstrating that it is both.

Research at the Harvard Medical School and elsewhere is showing that a change in the mind-set or attitude of a patient alters their neuro-chemistry whether in controlled laboratory studies or in the clinic. Patients affected by pain and debility, look to doctors and allied health professionals for the words, gestures and deeds that reinforce their belief in medicine's power and reinforce our expectation that we will benefit from an intervention. Research is showing that neuro-chemical changes are induced that have a catalytic effect on many body systems.

Belief, attitude and expectation - perhaps we could label these as "hope" - can be embedded and shaped by the encounter between patient and the universe of care they receive. This hope produces an effect that can block pain by releasing endorphins and enkephalins that in turn influence fundamental processes such as respiration, circulation, elimination and motor function. Hope is the leverage that can start a cascade of physical effects making improvement much more likely.

One of the reasonable questions we could pose is

"If we accept that placebo is real - how can we harness this power and really direct it in clinical situations to support our other strategies?"


As more people start to pose this question it becomes much more likely that research could be directed away from just demonstrating the effect exists, and more toward research and practice that can help us harnesses this power.

The placebo's effect in treating depression was considered in a 1998 meta-analysis (bringing together related journal articles to provide a potentially stronger evidence base). The authors suggested that the placebo effect might account for up to one third of the clinical benefit of modern antidepressants. Some authors claim an even stronger improvement. This level of benefit is highly significant and certainly worthy of attention. It causes challenges for pharmaceutical companies who need to demonstrate that their formulations produce a measurable effect compared with placebo.

Pharmaceutical companies are interested in placebo because it complicates the clinical trial process. The Wall St Journal in 2004 noted that clinical trials are finding that placebos are almost as effective as formulated antidepressants. For example, Fluoxetine (Brand name Prozac) gave a response score of 8.30 compared with a response score of 7.34 for placebo. The score was measured over five trials and noted the average improvement, measured in points on a standard, validated scale to assess the severity of depression. Other formulations exhibit similar levels of performance relative to placebo.

Placebo response to antidepressants is particularly high in young people. A trial for Zoloft found improvements in 59% of children given a placebo compared with 69% who took an active medicine.

You see, clinical trials deal with statistics and typically require large numbers of participants to be of any value. The smaller the effect that is to be detected the larger the trial needs to be. What we do know is that some individuals respond very powerfully to placebo and others don't - and we don't yet know how to reliably spot who is who beforehand. For example, to get permission to market a new drug, the manufacturer most convince a regulatory agency that its product performs better than placebo in at least two large, controlled trials. If the makers could identify ahead of time the individuals that do well on placebo, then they could eliminate them from the trial, allowing trails to be smaller and conducted more quickly. This is important because antidepressants represent perhaps $20 billion in world-wide sales.

Recent studies of patients with Parkinson's disease, a condition in which one part of the brain (the striatum) stops producing enough dopamine to support normal movement and muscle control. Drugs called dopamine antagonists can provide some symptomatic relief by substituting for the missing dopamine.

Funny thing is that placebo can bring relief too - and in ways that are more than just allowing people to ignore their symptoms.

Scientists at the University of British Columbia found that placebos improved the symptoms of Parkinson's disease in some subjects and that in these individuals increased levels of dopamine were being generated in the striatum of their brains.

The majority of placebo-effect studies have focused on pain. These days we have the technology to monitor brain chemistry and activity through the use of functional magnetic resonance imaging.

Some of the factors are coming to light:

The Person
Studies suggest that trial participants are more likely to experience a placebo response if they have strong belief in the treatment they are helping researchers evaluate.

The Clinician
Doctors, clinicians and the individuals involved in the care of a person may also influence outcomes. Research has shown that when physicians are hopeful and enthusiastic about the active treatment in a study, patients are more responsive to a placebo. The effect of medical and nursing care (the "Hawthorne" and "halo" effects) and the nature of the patient-doctor relationship is definite although some people would dispute that this is part of the placebo effect.

The Particular Condition or Illness
It is suspected that placebo will work better for some conditions than others. Studies suggest that problems with vague causes such as aches and pains or fatigue, are more responsive than conditions where the cause is obvious and structural. For example, it's hard to ignore the "reality" of a broken bone or an amputated limb. By the same token, placebos have tended to work more consistently with acute pain than chronic pain. Maybe the issue here is the ability of the person to secure strong enough emotional leverage or hope.

The Treatment
The usual placebos used in trials have been inert pills that have no direct physical effects. In some studies though, patients have received an active placebo that cause symptoms that the patient will notice (raised heart rate for example) but has no therapeutic effect. Not surprisingly the active placebo produces a stronger response perhaps because it is easier for the patients to believe they are receiving an active drug.

The Three Legged Trial
Some researchers have pointed out that trials would be better conducted with three legs. One group would receive the active treatment, one the placebo and a third would receive nothing. The idea being that many patients might have got better on their own.

When we consider the placebo effect we are mapping some aspects of the mind-body connection and opening the lid on some of the pathways through which mental factors alter people's symptoms, health, or even an underlying disease.


Derek Jones Ph.D., M.B.A.
Bioengineer, Entrepreneur, Business Coach, Author, Speaker

Director, CATA Corporate Development Ltd - High performance business coaching
Director, Anatomical Concepts (UK) Ltd - your partners with clinically effective orthotic solutions
Weblog - Hero'sCode

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