The Placebo Effect

Evidence That Antidepressants May Not Be Doing All the Work

One very important topic of debate surrounding the issue of antidepressants is that of the placebo effect. Studies have shown that anywhere from 30 to 40 percent of the effects of antidepressants stems from a placebo effect, where people believe that taking the drug will make their depression go away, creating a spark of hope that in itself helps relieve their illness (Kirsch & Sapirstein, 1999). There has been much research in the area of placebo effects and expectancies (meaning that the fact that someone expects a certain response may actually create that response). There has also been much debate over the interpretation and meaning of the results.

RESPONSE EXPECTANCIES

Kirsch did an experiment in 1999 about response expectancies that showed support for the existence of the placebo effect in a way that could have strong implications on treatments for depression. They predicted that what a person expects to happen will trigger his or her automatic emotions, behaviors and thoughts, and these will cause the expected event to occur. Response expectancies have been proven to affect the experience and physiology of placebo effects by automatically triggering those bodily responses that naturally would have occured in response to, say, a drug. One example of this is the body's natural reaction to reduce pain in response to either real or placebo analgesia.

DEPRESSION AS AN AUTOMATIC RESPONSE

Emotions, and the way we act because of them, often seem out of our control, as if they are ingrained in our bodies to react automatically to certain situations. Often, for example, we will burst into laughter or into tears unexpectedly. According to Kirsch, many of these feelings are in fact automatic, occurring whether we want them to or not, and one of these is depression. One indicator that they are automatic is that they are often the opposite reactions to what we would want, such as being depressed. What is interesting, which Kirsch demonstrated in 1985, is that expecting our body to automatically have these feelings and thoughts in response to a situation can in turn create the situation. Kirsch explains how the self-fulfilling prophecy created by the expectancies is very important in the way a person deals with depression, largely in terms of treatment and further prevention. Response expectancies created by placebos have shown to cause changes in depression patients.

STRONG RESEARCH SUPPORTING THE PLACEBO EFFECT

While some people do not believe in placebo drugs or have done studies proving the placebo effect does not exist in respect to depression, there is research in support that is hard to argue against. Depression, compared to other mental health problems, is one disease that can very likely be affected by the responses that a person is anticipating. In this case it is the feelings created by antidepressants, whether real or placebo. In a study by Kirsch and Sapirstein in 1999, 75% of the effect of antidepressants on depression patients was also found when an inactive placebo was used. After accounting for outside variables they estimated that 50% of the effect of the drug was due to expectancies, while only 25% of it was due to the actual drug.

UNRELATED TYPES OF DRUGS ALSO WORK

In a continuation of this study they examined different types of antidepressants and discovered that they all have approximately the same effect size on depression patients as well as compared to placebos. The most fascinating thing they found though, was when they gave one control group other types of active drugs that had no relation to depression. The effect of any of these drugs was as substantial as any of the antidepressants, and the placebo once again had 75% of the effect size. This shows that not only do placebos affect depression, but also that completely inappropriate drugs can have the same effect that any antidepressant will. The logic behind this is that if you are taking active drugs, they are going to affect your body's physiology somehow. Since you are expecting to have a reaction to the antidepressants, you notice the changes in your body due to the other drugs, attribute them to the antidepressants and believe that they are working. This simple act of expecting the drug to make you feel side effects and then feeling side effects makes you think the drug is working and making you less depressed. This hope and belief, as shown, is largely what improves depression.

WHAT'S ALL THE FUSS ABOUT THEN?

What many people wonder then is what the big boom to prescribe antidepressants to everyone who seems a little depressed is all about, if it is possible to feel better by changing your cognitive attitude and not taking drugs. Part of this so-called "serotonin revolution" is due to the quickness with which doctors are willing to diagnose a patient with depression and send them home with a nice little bottle of Prozac. But there are others who argue that antidepressants have a much greater curative value biologically than Kirsch gives them credit for. Sam Hamburg explains that much of the research done by Kirsch could have been interpreted differently than it was, offering explanations for why Kirsch's research and conclusion about antidepressants may not represent the drugs (Hamburg, 2000). One of his main points is the placebo effect does not exist in actual clinical practice anywhere near the amount it does in research, indicating that something about the experiment biased the results. It is important to remember that the point of doing research is so that it can be applied to the real world. If the results are not the same, the outcomes of the research are futile. These debates leave us with much to ponder about antidepressants and why the frequent prescription of them is on the increase.