Antidepressant placebos remain a steady presence in clinical experiments, but not in public knowledge
The McGill Daily
March 10, 2011
It’s the classic situation: with an imminent exam and a carefully planned cramming schedule, you awake one morning with the all too familiar symptoms of a common cold. Feeling sorry for yourself between sniffles and coughs, you self-medicate with the usual blend of OJ, vitamins and copious amounts of water, fervently hoping for a rapid recovery.
Most of us who catch a cold end up taking desperate measures to fix the situation, regardless of whether such measures are founded on scientific truth. Increased vitamin C intake? Not only is there zero proof that it prevents colds, there’s also none that it expedites recovery, according to a paper in Evidence-Based Child Health. Herbal remedies like echinacea? Hot liquids? Beyond the latter’s ability to provide temporary relief, neither will provide much help.
Indeed, the most powerful panacea of them all is our own gullible mind. Once convinced of the effectiveness of a cold cure through a lifetime of anecdotal accounts and lore, many of us will start feeling better after a day of downing orange juice even though it serves as much of a medical purpose as twiddling your thumbs. And while juice manufacturers don’t proclaim cold-fighting abilities on every carton, another highly lucrative industry relying heavily on the placebo effect does assert a claim: that antidepressants cure depression.
Beginning in 1998, a series of studies have repeatedly questioned the difference in efficacies between antidepressant drugs and placebos. Pioneering analysis work done by University of Connecticut researchers Irving Kirsch and Guy Sapirstein confirmed the effectiveness of antidepressants – but also their inert counterparts. In 38 studies conducted with over 3,000 depressed patients, placebos improved symptoms 75 per cent as much as legitimate medications.
“We wondered, what’s going on?” said Kirsch in a 2010 interview with Newsweek. The medical community, skeptical of his analysis, asked him to instigate a more comprehensive study with the results of all clinical trials conducted by antidepressant manufacturers, including those unpublished – 47 studies in total.
Over half of the studies showed no significant difference in the depression-alleviating effects of a medicated versus non-medicated pill. With this more thorough analysis, which now included strategically unpublished studies from pharmaceutical companies, placebos were shown to improve symptoms 82 per cent as much as the real pill.
Now also consider that any apparent advantage of the genuine medication might be more the mind’s handiwork than chemical effect. Patients in double blind clinical trials, where neither experimenter nor patient know if a placebo or real drug has been taken, may easily determine which is the placebo. The obvious side effects of the genuine pill, such as headaches or nausea, may alert the patient to which study group they’ve been placed in, and the knowledge that their pill is medicated may be enough to alleviate their depression.
Are antidepressant drugs really “a triumph of marketing over science,” as researchers have claimed? Kirsch and other experts are convinced that antidepressants do not chemically cure depression. A British agency charged with determining which treatments are effective enough for government funding has stopped endorsing antidepressants as the default treatment for anything but the most severe forms of depression. And drug manufacturers themselves don’t deny Kirch’s data. A spokesperson for Pfizer, producer of Zoloft, has alluded to the existence of a “wealth of scientific evidence documenting [antidepressants’] effects,” yet the fact that treatment “commonly fail[s] to separate from placebo” is “well known by the FDA, academia, and industry.”
However, if experts and antidepressant manufacturers are aware of this, the general public certainly isn’t. Which is precisely why antidepressants work. Without the knowledge that even manufacturers of medications aren’t completely convinced of their product’s superiority, antidepressants will continue to be effective. This not a recommendation for current users to halt taking the pills; abrupt withdrawal is extremely dangerous, and there is still a range of perspectives on the topic of antidepressants versus sugar pills.
But you have it. Millions of people every year feel better, simply because they believe they’ll feel better. We’ve recovered from colds, headaches, pain, and depression, courtesy of the placebo effect. After all, there’s something to be said for feeling better.