Have there been any studies that show how long the placebo effect can last? I was talking with a friend over the weekend and I mentioned that since I started taking vitamins 15 years ago I have felt better in general and not gotten sick (colds and flu) nearly as often. Now there are lot of reasons why that could be the case, maybe I’m eating better now or sleeping more than I used to, but if I stop taking vitamins for a few days I start to feel more run down than usual. He replied that since I wanted to believe that vitamins were helping me it was simply a result of the placebo effect. I said that I didn’t think the placebo effect could last for 15 years, and that sooner or later it would eventually wear off.
So what’s the straight dope? Could someone benefit from the placebo effect for many years? And how do I know if I am suffering from the placebo effect or not?
If you believe going off vitamins could make you feel worse, you may feel worse through the nocebo effect, even though your body is continuing the get all the vitamins it needs through your food.
The “nocebo” and “placebo” effect seem to me to be the same thing. You take something that is inert that you think will have either a positive or negative effect on you, and it does, for some period of time.
So my question is the same. Can someone benefit/suffer from the placebo/nocebo effect for a very long period of time or does the effect usually wear off after a new days, weeks or months?
I believe what ramel was saying is that you may have experienced a “nocebo effect” from NOT taking your vitamins, i.e. you expected that not taking your vitamins would lead to negative side effects and it did. That seems far more likely to me than the placebo effect lasting for 15 years.
As far as the duration of the placebo effect goes, wikipedia does link to a few journal articles on the matter.
I’m not sure I understand the question. The placebo effect is coming from within you. It’s also described as response expectancy theory, and should work as long as you expect that it should work. (Conceptualizing it as response expectancy should also help us to ever avoid saying the word “nocebo” ever again.)
The way you describe the effect in the OP sounds almost like you regard it as a property of the vitamins, which would mean that they aren’t inert and that their effect could not be described as placebo.
I could never find the study to cite it now, but a long time ago I heard of a nutritional study that compared what people ate and what they thought about it with general health. The conclusion was that there is a positive affect to believing that one has a healthy diet even if it is not true. If you believe you are eating healthy, it is healthier for you.
I would just like to point out that not everyone is subject to the placebo effect. I have had my 2 former psychiatrists tell me that a med would have a certain positive effect. I’ve tried it and waited to see the effect, but it never happened.
I have also taken supplements for various purposes - in one case, niacin to tame early morning panic attacks when I was much younger. The attacks would go away, I would forget to take the niacin and they would come back. It took several cycles like this before I finally realized that the niacin was in fact having the desired effect and made a concerted effort to take it on a regular basis - at least until I “outgrew” the attacks.
Today I have a very similar problem and niacin is completely ineffective, even though I EXPECTED that it would be. Now only an anti-psychotic seems to be effective. But before I got to that point, I tried other meds also expecting them to work, but they didn’t.
What I find interesting is that this apparent immunity to the placebo effect also makes me immune to marketing hype when it relates to something that depends primarily on subjective opinion - like how good a product tastes for example.
As to supplements, if you review the recommended daily value of certain nutrients (such as magnesium and zinc) and look up the amount of those minerals found in your average daily diet, you will be very surprised to find out that there is very little chance you are getting anything close to 100% of what is recommended. This is probably true for other nutrients as well. Zinc at 11mg/day is possible to get - especially if you like oysters - Zinc - Health Professional Fact Sheet. But magnesium is very difficult - especially if you are on any kind of diet. See - Magnesium - Health Professional Fact Sheet. I have read elsewhere however that the RDA (no longer used) is around 800mg/day so I’m not sure when this was changed to 420.
The “placebo effect” is a combination of effects of experiments, not of treatments. Only one of those effects is feeling better because you expect to feel better, and that particular effect will NOT stop you getting a cold or flu.
In the case described by the OP, do you really remember your rate of cold and flu 15 years ago? Did you take careful records back then, and have you taken careful records for 15 years? If not, then you need to be aware that your 1 person experiment is going to be distorted by your own memory seeing what it wants to see.
Was the reason you started taking vitamins because you had an unusually high rate of illness? In that case, your 1 person experiment is going to suffer from regression to the mean - in a naturally varying sample, extreme cases are more likely to head towards the mean than away from it.
Are you measuring colds and flu yourself, or with an independent person who doesn’t know whether you’re taking vitamins? If it is yourself, then you have observer bias, one of many uncontrolled factors that placebo controlled experiments can compensate.
In short, yes placebo lasts forever, but not because it makes you better forever.
What do you mean by this? The placebo effect is independent of experiments, and is very likely at least a component of many treatments. It is a naturally occurring phenomenon, which is why it has to be controlled for in experiments.
I’m trying to recall exactly where I read about this (probably in Irving Kirsh’s Changing Expectations book), but I believe he demonstrated some effects for response expectancies even when people were told that they were receiving a placebo.
Also, might not your body be used to high levels of vitamins (sort of an addiction), so when you stop taking them you do have a physical reaction? If so, this would not be placebo/nocebo effect.
Obviously not a doc, but 15 years of vitamins has to have some lasting effects on your body beyond providing your daily doses of vitamins.
One thing that does occur that is related to the placebo effect, is that when patients are monitored - either as part of a study or just by their physician - they tend to alter their behavior. That’s why so many diets work in the short term. When people know that someone is going to be weighing them, checking their blood pressure, cholesterol, etc., they tend to eat healthier, smoke less, exercise more, and generally lead a healthier lifestyle.
In your case it may be that whatever prevented you from taking the vitamins (e.g., out late, hung over, stress) is the thing that’s making you feel worse.
I don’t know if the anecdotes were true, but I recall during the 60s, when the term ‘placebo’ was not well known, the story that doctors would tell patients they were prescribing 20mg of placebo daily, and telling patients that it might help. I’ve assumed this was another myth, but who knows.
So were they told they were recieving ‘placebo’, a term they didn’t understand, or a ‘placebo’ which they understood to be nothing. And then, how do you factor the ‘placebo effect’ in the study of people taking placebos?