Trendy Medicines
Herding can be a very powerful factor in people’s decision making, and therefore a potentially dangerous one. One of the best examples of this possible danger is the rise of Prozac.
Prozac was produced by Eli Lilly in the 1980s as an antidepressant. It was marketed as a wonder drug that corrected a “chemical imbalance” in the brain—a serotonin deficiency. Many hailed it as a miracle pill. Some said they felt like a completely different person on the drug. The FDA approved Prozac in 1987. Within one year, it had been prescribed to nearly 2.5 million Americans. By 2002, that number had reached over 30 million. Today, 10% of Americans over the age of six regularly take antidepressants. In fact, antipsychotics have replaced cholesterol-lowering pills as the top-selling class of drugs in the United States.
So what happened? It’s certainly possible that more people were just getting the help they needed. Many experts state that depression is highly under-diagnosed and is therefore often left untreated. After all, there were millions of people taking Prozac who adamantly defended their magic pill.
Marcia Angell, however, disagrees. And she’s not alone. Many experts today consider the unprecedented rise of Prozac to be largely due to its marketing. In fact, clinical trials found that Prozac was no more effective than active placebos (placebos that give participants a noticeable, harmless side effect) in helping patients. Nearly all of the participants who were on Prozac and on the active placebos reported the same positive effects.
This suggests that Prozac’s popularity was due less in part to its effectiveness as an antidepressant, and more to the power of information cascades. As more people became convinced by advertising that this drug would help them feel better, they successfully convinced others in turn to try it. People’s decision to try Prozac exactly fits the information cascade scenario. They imitated the behavior of others by drawing rational inferences from limited information. Eli Lilly had done several studies on Prozac before releasing it. The positive ones were splashed across medical journals, while the negative ones were labeled “proprietary” and therefore kept confidential within the FDA. Since there were so many studies with positive results, and so many others had found “success” with Prozac, it becomes much clearer why nearly 10% of the country was taking the pill.
Prozac is a good example of the potential dangers of information cascades, but it isn’t the only one. There seems to be a drug for everything these days. Television ads market pills that cure “ailments” such as low testosterone in middle-aged men (a very natural part of aging) or “Restless Leg Syndrome”. With the research not always certain on the full, long-term health effects of these drugs, we can only hope that people avoid following the crowd when it comes to their medicines
http://www.nybooks.com/articles/archives/2011/jun/23/epidemic-mental-illness-why/?page=1
http://www.bbc.com/news/magazine-22040733