I'm a bit of a hypochondriac, so I'm fairly accustomed to taking regular trips to see the doctor - one of the perks of living in a socialist paradise is that this doesn't break the bank! Most people, however, tend to need a little extra push to get them to visit the doctor and stop soldiering on. Imagine then, after begrudgingly carting yourself all the way to the doctor's practice, she looks you up and down, scrawls something incomprehensible onto a little piece of paper (there must be a whole module titled 'How to write the unreadable' - I suspect it's a defense against lawsuits), and then says the following:
I think you're just overworked, which can take its toll. Here, take these pills which I've labelled 'medicine'. These pills have no direct physiological effects, but I am very confident that they will help with your symptoms. You'll feel better in no time.
"Medicine with no direct physiological effects?!" I hear you ask. "Strike her off, she's a quack!" I imagine you'd continue. And I'm right there with you! I want the good stuff! But let's hold fire on getting her medical license revoked for a second; assuming her diagnosis is correct, she might be onto something.
There is a growing body of evidence, spanning back not just decades but centuries, that in some situations, if you believe that you are receiving excellent care, your prognosis is improved. Your outlook is improved just by believing it is. This, in a nutshell, is the placebo effect, and for a long time it has been a tough pill for scientists to swallow. Luckily, science doesn't give up every time it finds something mysterious, but it has taken a while for this phenomenon to be taken seriously. And taken seriously it should, if we want to once and for all rid ourselves of some of the more dangerous alternative therapies out there.
Now, don't get me wrong, I'm not averse to all alternative therapies; I like a massage as much as the next guy. They feel nice. If they're a supplement to an otherwise healthy lifestyle, and their proponents don't suggest you sack your doctor and bin science, then fine! What's the harm? Some alternative therapies, however, are not so benign. Homeopaths don't want to know about radiotherapy, acupuncturists think a few needles will cure diabetes, and ear chandlers ... well the less said about that bundle of madness the better. That said, on the face of it, some of the more basic (and flawed, as we will see) experiments have provided pretty compelling evidence that all kinds of crazy treatments can help you feel better. Acupuncture, when compared to no treatment at all, is actually good for you.
That's right, lying down, listening to sounds of the ocean, and having needles stuck into your body is better than no pills at all for a range of maladies. Headaches are relieved, IBS severity lessens, common cold symptoms fade more quickly, and surgical recovery time is shortened. Does that mean it works? Yes and no, and a 2008 study in Harvard shows this nicely. Here, they set up a fake acupuncture session with IBS sufferers, where unbeknownst to the patients, the needles never actually penetrated their skin, but all the other aspects of the acupuncture treatment, such as the soothing music, the meditation, and the total undivided attention of a care-giver, remained the same. The results? Needle-less acupuncture also works! It's a miracle! They also found that the more attentive and caring the care-giver, the better the results were. The attentive care-giver was leading to a lessening of the patient's symptoms, exactly as we'd expect from the placebo effect. So what exactly were the needles supposed to be doing again?
Acupuncture: putting the BS in IBS treatment.
This is why when I'm confronted with evidence that, for example, homeopathy works, and I respond with "how do you know it's not just a placebo effect?", I'm not asking "Are you really sure it works? Like really works?!", I'm asking "Does it work well if the patient doesn't know what's happening? Would homeopathy help the unconscious? And importantly, would it perform better than a sugar pill in a carefully controlled trial?"
This last question is why all new forms of treatment are tested in comparison to a placebo group. There's a new Alzheimer's drug every other week, and they're all given the same type of two-sided trial; one group of Alzheimer's sufferers are given the drug in question, and another group (with as similar circumstances as possible) are given something akin to a sugar pill or a saline solution for comparison. Crucially, none of the patients know which group they are in, and actually, wherever possible, it's also important that the doctors not know who is in which group, so the doctors' expectations don't infect the results. It might seem harsh to knowingly give a person with a deadly disease little more than a pat on the head, but the doctors are also considering the thousands of lives that could be affected in the future by misinterpreting results and prescribing something that is ineffective. If we waste millions of pounds and years of effort prescribing a dud drug, we're left with a much bigger tragedy than that of the poor souls who get the placebo. Also, there's always the chance that the drug being tested will worsen a patient's outcome, and then you'd be glad of taking the sugar pill! Comparing against a placebo group in this way can be unfortunate for a few, but this type of trial is one of the most powerful and ethical tools we have.
Tests have to take the placebo effect into account, because we know that many forms of sham care, from sugar pills, to needles, to a simple "there there, who's a big boy?", somehow help the patient without offering any direct physiological effects. How do we define "help" though? After I've finally got my docs appointment, tell her about my itchy knee, and am told "Here, take these vitamins, and get out of my office!", I certainly feel better! But are there any objective measurable changes after being given a placebo? Other than in the totally measurable change in the spring in my step of course.
Well, sort of. The placebo effect seems to reduce injury recovery times (beyond what simple pain relief can explain away), and shortens the duration of some symptoms of viral/bacterial infection, suggesting a minor immune system boost ... but it doesn't affect everything.
Take the 2011 New England study in asthma treatment. One group of asthma sufferers were given a widely used drug that has a known measurable benefit to lung function, and two other groups were given either a placebo asthma drug or sham acupuncture (going after the acupuncturists again!). After the test, when they carried out lung function test, they found that the drug did what was expected and improved lung health, whereas the placebos had no effect. But, when the patients were asked how they felt they had improved in terms of breathing and comfort, all groups scored equally well! The placebo groups felt just as good as the medicine group, even though their lungs still looked like crap on a scanner. So, what's more important here? The physiological health of the patients' lungs, or the perceived well-being of the patients? I think this highlights the dangers of relying on the placebo as well as the dangers of relying on alternative therapies, as it proves that we are terrible judges of our own health, and can't be relied upon to know whether we are about to go into respiratory collapse.
In a broader sense, though, how important is a general feeling of well-being in a patient? Doctors aren't there just to fix our organs after all, they're there to relieve discomfort of all sorts, and the placebo can do that. So should we try and take advantage of the placebo wherever possible? Questions like that are tough for doctors, because any attempt to administer a placebo causes conflict between two of their fundamental duties of care:
- Give your patient the best possible treatment.
- At all times, tell your patient the truth.
How do you take advantage of the placebo effect while remaining honest? If your solution would be to allow good-intentioned doctors the power to lie to their patients as they please (doctors are the experts after all!), I would put it to you that in the past, doctors that have been less open about their placebo prescriptions have tended to prescribe sedatives and antibiotics where none are needed. Their intentions to give a placebo may have been honorable, but overuse of sedatives can have some very serious negative side effects, and over-prescription of antibiotics is partly responsible (along with the meat industry which I'll get to another day) for the deadly antibiotic resistant bacterial strains (known colloquially as "super bugs") such as MRSA. (I searched for some images of MRSA to give this paragraph a bit more punch, and was left terrified. Thanks again hypochondria!)
Interestingly, one study showed that it may also be completely unnecessary for doctors to lie outright, as telling a patient they're receiving a placebo doesn't entirely remove the placebo's effects. If my doctor looks me up and down, and reels off the monologue I opened this blog with, I will likely get some placebo benefit from simply feeling like I'm in good hands (albeit a smaller benefit than if she had said "Here's the cure you're looking for Kyle. Look, it says 'CURE' in all caps on the bottle").
If you've gotten this far, you've probably noticed I've skirted around an important part of the story: how does the placebo work?! The reason I skirt is because, honestly, it's not really well understood. Brain scans of people taking a placebo have revealed that endorphins - the body's natural pain killers - are released when a placebo is taken, but to me this feels like we're just measuring the results and not the cause - the endorphins surely don't cause the placebo effect, the placebo effect causes the endorphin release!
In terms of the pain relief aspect, I think nothing more than psychology is needed as an explanation - it is easy to ignore a small wound if we're not aware of it, but the second you see the blood pouring, suddenly our brains tell us to whelp with pain, and similarly, if we feel a drug go into our veins that we're expecting to relieve pain, it shouldn't be surprising that we will convince ourselves that our pain is lessened. This is expectancy theory, and it is probably strengthened by classic conditioning, where positive outcomes from getting medical treatment in the past have conditioned us to anticipate positive outcomes from treatment now, even if the treatment is a sham (if expectancy theory and classical conditioning kind of sound the same, it is because they are very much related).
As for the recovery time aspect of the placebo, I think it's a little more complicated, but not much. It is well documented that general anxiety physiologically mimics the fight or flight response in creating a constant sense of dread, which in turn inhibits sleep - the very time when the immune system and bodily healing does the majority of its work. Further, when fight or flight mode kicks in, certain bodily functions basically shut down to divert energy towards keeping us ready to go at a moment's notice, and one of those systems that is lose is the digestive system (no one gets hungry when they're running from a bear after all!). Scientists have been learning a lot in recent years about the complicated interplay between having healthy gut bacteria, getting the right amount of sleep, and having a working immune/recovery system - the outcry for fecal (poo) transplants to help with C-Diff infections (which has been proven to be highly effective) is testament to the surprising effect gut bacteria has on our health - so it's hardly surprising that anxiety is bad for you.
When I take all this info on board, my feeling (and really, it is little more than just a feeling) is that being cared for and being given a positive outlook simply has the opposite effect of anxiety, and gives a little boost to all those things that our bodies are naturally good at at times of calm. A dose of the placebo, then, is just our way of getting our body to stop panicking and get its act together.
The final aspect of the placebo I'd like to point out is that, sadly, its effects don't last. Not one study has shown a steady placebo dose to be effective long-term with chronic conditions ... Bummer. And here I was starting to think I could cure all my ails with a daily sugar pill.
To round this all off, if there's one take away from this blog, it should be this: the placebo effect is powerful, but do not rely on it. It won't cure you of anything serious, and it won't last. At best, it could make you feel better for a while, and get you out of that hospital bed sooner. On the other hand, it could be peddled by charlatans as an alternative therapy in the place of real working medicine, or worse, give you a false sense of ease when your organs are on the verge of failure. And on that note, I have some symptoms I need to Google.
TL;DR: Placebos are good, but they're no replacement for a good old fashioned medical exam ... so go get that thing checked out.
Note: There is some contention over whether the placebo effect exists at all beyond subjective results. Hróbjartsson & Gøtzsche argue that any long term effect the placebo has in objective outcomes (such as bone healing time) go away when you take appropriate sample sizes and remove effects of bias and regression to the mean ... But this is a somewhat contentious and minority viewpoint, and I mention it just to cover all bases.
Placebo band image attribution: By Henry W. Laurisch (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons.
Acupuncture victim image attribution: By mscaprikell [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons.
Miracle cure attribution: By FDA graphic by Michael J. Ermarth ("Miracle Cure!" Health Fraud Scams) [Public domain], via Wikimedia Commons.