<p>As far as I know, it has not been shown that a positive attitude has any effect on the immune system (ignoring the <a href="http://en.wikipedia.org/wiki/Placebo#Clinical_significance" rel="nofollow">less significant placebo effect</a>).  What has been shown is that long-term stress has a negative effect on the immune system.  <a href="http://psycnet.apa.org/psycinfo/2004-15935-004" rel="nofollow">Short-term stress actually has a positive effect on the immune system</a>, but long-term stress has been correlated with several affecting mechanisms: lower white blood cell count, <a href="http://www.ncbi.nlm.nih.gov/pubmed/12693607" rel="nofollow">too much cytokine production</a>.  </p>

<p>The following study found lots of mixed results.  A typical sign that there's really no clear answer to the question.  When there are so many confounding results, it's easy for people to only take the half they agree with, so we should be wary of our propensity to do so when we want to hear a particular answer.</p>

<blockquote>
  <p>The failure of optimism to consistently predict better physical health indicators and outcomes is consistent with this pessimistic view of optimism: “The best doesn't always occur. When things go wrong in a big way, the optimist may be particularly vulnerable.”</p>
</blockquote>

<p>...</p>

<blockquote>
  <p>I have suggested an alternative hypothesis to explain negative effects of optimism on the immune system (see Fig. 1; Segerstrom, 2001; Segerstrom et al., 2003; Solberg Nes et al., in press). This hypothesis specifies that under difficult circumstances, more optimistic people remain engaged with those circumstances whereas more pessimistic people disengage, avoid, or give up. Giving up can be a physiologically protective response because stressor exposure is minimized in the short term by giving up rather than remaining engaged...</p>
</blockquote>

<p><a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1948078/" rel="nofollow">http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1948078/</a></p>

CC BY-SA 3.0
2012-08-14T16:57:21.753Z
Well the mechanism could be social - positive emotions could elicit and strengthen social bonds which could affect some socially mediated source like hormones--> NTs. Thus, higher cortical processes can affect immune system functioning indirectly through social information.
David Winer
CC BY-SA 3.0
2012-08-14T16:58:18.867Z
I was thinking there must be studies done to test the effect of positive attitude on cancer recovery, which I thought was something doctors recommend, but I see now there are is no such evidence.
David Winer
CC BY-SA 3.0
2012-08-14T16:59:59.863Z
Aren't there sometimes significant results from placebo effect? Even if they are minimal, is it just through unconscious changes in behavior that better the recovery process? Even that is an answer, if there have been studies.
David Winer
CC BY-SA 3.0
2012-08-14T17:00:03.783Z
I am a little bit skeptical of this answer. Writing off the placebo effect as something insignificant is not appropriate in all cases, I would appreciate it if you expanded on your reasoning behind this and/or provided some references. I understand it is really hard to find references for negative claims, but somehow this seems to be too simple of an explanation to be true.
Artem Kaznatcheev
CC BY-SA 3.0
2012-08-14T17:04:59.950Z
I'm with @ArtemKaznatcheev, and I think this could potentially be an important question to have answered on the site, so having some reflection of the existing research would make it all the more valuable.
Chuck Sherrington
CC BY-SA 3.0
2012-08-15T00:57:37.990Z
The placebo effect is used as a control.  We test placebo effect *against* the effectiveness of drugs.  If a drug performs as well as a placebo, we consider the drug to not be effective; we use the placebo to *define* significance.  The placebo effect does not work consistently. Doctors prescribe placebos to people they think are not having real physiological symptoms.  I've included a wiki link in my answer that references two studies.
Keegan Keplinger
CC BY-SA 3.0
2012-08-15T02:01:45.667Z
Btw, that's not to say that I find your skepticism unreasonable.
Keegan Keplinger
CC BY-SA 3.0
2014-05-09T14:30:26.953Z
@ArtemKaznatcheev, I have provided more evidence for this answer.
Keegan Keplinger
CC BY-SA 3.0
2014-05-09T15:51:31.033Z
Thanks for the reference @KeeganKeplinger, the reason that I was skeptical is that one would expect the placebo effect and positive attitude to work via the same mechanism, thus there is no clear way to do a placebo control for 'positivity' as you would for a drug. You could, however, design an experiment where every day the patient is asked to list and focus on the positive or negative (depending on which experimental group they are in) effects of their situation, and then compare the results of the two groups.
Artem Kaznatcheev
CC BY-SA 3.0
2012-08-14T05:40:47.980Z
2014-05-09T14:25:59.140Z
2014-05-09T14:25:59.140Z
Keegan Keplinger
<p>It seems likely that a positive attitude can speed up the healing process. but I can't decide by what mechanism it would operate by. </p>

<h3>Questions</h3>

<ul>
<li>Does having a positive attitude improve immune system functioning?</li>
<li>If so, what is the mechanism by which this occurs?</li>
</ul>

<p><strong>Initial thoughts:</strong> Is it the inhibition of some sort of stress cortisol? 
The answer seems like it would have to do with how the placebo effect or hypnosis suggestion functions.</p>

CC BY-SA 3.0
2012-08-13T03:23:35.160Z
when looking for possible connections, it is best not to make implicit assumptions. This question will be greatly improved if you do the [initial research](http://meta.cogsci.stackexchange.com/q/66/29) and include an example reference (like [this](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1246362/?tool=pmcentrez) but one you have taken time to look over)  to frame your question. Also, as written it is not clear if you are asking for the specific mechanism (and at what level of description) or if you are just looking for general data on relationship between place-effect and recovery time.
Artem Kaznatcheev
CC BY-SA 3.0
2012-08-13T15:55:23.670Z
Thank you, the question looks greatly improved! As you predicted, I'm looking for the mechanism if there is one.
David Winer
CC BY-SA 3.0
2012-09-08T22:36:09.973Z
I saw something today about this in an [interview with Gabor Mate](http://www.democracynow.org/2010/12/24/dr_gabor_mat_on_the_stress) (near the end, ~40 minutes, but I suggest watching the whole interview, good stuff).  Dr. Mate brings up several studies.  He called the discipline [Psychoneuroimmunology](http://en.wikipedia.org/wiki/Psychoneuroimmunology)
Keegan Keplinger
<physiology><health-psychology><positive-thinking>
What is the mechanism explaining the effect of a positive attitude on immune system functioning?
David Winer
# What is the mechanism explaining the effect of a positive attitude on immune system functioning?

(Asked by: username_0 on 2012-08-13)

It seems likely that a positive attitude can speed up the healing process. but I can't decide by what mechanism it would operate by.

### Questions

* Does having a positive attitude improve immune system functioning?
* If so, what is the mechanism by which this occurs?

**Initial thoughts:** Is it the inhibition of some sort of stress cortisol?
The answer seems like it would have to do with how the placebo effect or hypnosis suggestion functions.

**Tags:** physiology, health-psychology, positive-thinking

> **Comments:**
> **username_1**: when looking for possible connections, it is best not to make implicit assumptions. This question will be greatly improved if you do the [initial research](http://meta.cogsci.stackexchange.com/q/66/29) and include an example reference (like [this](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1246362/?tool=pmcentrez) but one you have taken time to look over)  to frame your question. Also, as written it is not clear if you are asking for the specific mechanism (and at what level of description) or if you are just looking for general data on relationship between place-effect and recovery time.  
> **username_0**: Thank you, the question looks greatly improved! As you predicted, I'm looking for the mechanism if there is one.  
> **username_2**: I saw something today about this in an [interview with Gabor Mate](http://www.democracynow.org/2010/12/24/dr_gabor_mat_on_the_stress) (near the end, ~40 minutes, but I suggest watching the whole interview, good stuff).  Dr. Mate brings up several studies.  He called the discipline [Psychoneuroimmunology](http://en.wikipedia.org/wiki/Psychoneuroimmunology)  

---

## 1 answers

### Answer by username_2 on 2012-08-14. Score: 6

As far as I know, it has not been shown that a positive attitude has any effect on the immune system (ignoring the [less significant placebo effect](http://en.wikipedia.org/wiki/Placebo#Clinical_significance)). What has been shown is that long-term stress has a negative effect on the immune system. [Short-term stress actually has a positive effect on the immune system](http://psycnet.apa.org/psycinfo/2004-15935-004), but long-term stress has been correlated with several affecting mechanisms: lower white blood cell count, [too much cytokine production](http://www.ncbi.nlm.nih.gov/pubmed/12693607).

The following study found lots of mixed results. A typical sign that there's really no clear answer to the question. When there are so many confounding results, it's easy for people to only take the half they agree with, so we should be wary of our propensity to do so when we want to hear a particular answer.

> The failure of optimism to consistently predict better physical health indicators and outcomes is consistent with this pessimistic view of optimism: “The best doesn't always occur. When things go wrong in a big way, the optimist may be particularly vulnerable.”

...

> I have suggested an alternative hypothesis to explain negative effects of optimism on the immune system (see Fig. 1; Segerstrom, 2001; Segerstrom et al., 2003; Solberg Nes et al., in press). This hypothesis specifies that under difficult circumstances, more optimistic people remain engaged with those circumstances whereas more pessimistic people disengage, avoid, or give up. Giving up can be a physiologically protective response because stressor exposure is minimized in the short term by giving up rather than remaining engaged...

<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1948078/>

> **Comments:**
> **username_0**: Well the mechanism could be social - positive emotions could elicit and strengthen social bonds which could affect some socially mediated source like hormones--> NTs. Thus, higher cortical processes can affect immune system functioning indirectly through social information.  
> **username_0**: I was thinking there must be studies done to test the effect of positive attitude on cancer recovery, which I thought was something doctors recommend, but I see now there are is no such evidence.  
> **username_0**: Aren't there sometimes significant results from placebo effect? Even if they are minimal, is it just through unconscious changes in behavior that better the recovery process? Even that is an answer, if there have been studies.  
> **username_1**: I am a little bit skeptical of this answer. Writing off the placebo effect as something insignificant is not appropriate in all cases, I would appreciate it if you expanded on your reasoning behind this and/or provided some references. I understand it is really hard to find references for negative claims, but somehow this seems to be too simple of an explanation to be true.  
> **username_3**: I'm with @ArtemKaznatcheev, and I think this could potentially be an important question to have answered on the site, so having some reflection of the existing research would make it all the more valuable.  
> **username_2**: The placebo effect is used as a control.  We test placebo effect *against* the effectiveness of drugs.  If a drug performs as well as a placebo, we consider the drug to not be effective; we use the placebo to *define* significance.  The placebo effect does not work consistently. Doctors prescribe placebos to people they think are not having real physiological symptoms.  I've included a wiki link in my answer that references two studies.  
> **username_2**: Btw, that's not to say that I find your skepticism unreasonable.  
> **username_2**: @ArtemKaznatcheev, I have provided more evidence for this answer.  
> **username_1**: Thanks for the reference @KeeganKeplinger, the reason that I was skeptical is that one would expect the placebo effect and positive attitude to work via the same mechanism, thus there is no clear way to do a placebo control for 'positivity' as you would for a drug. You could, however, design an experiment where every day the patient is asked to list and focus on the positive or negative (depending on which experimental group they are in) effects of their situation, and then compare the results of the two groups.  

---

