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News: New insights into placebo effect

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  • Robert Karl Stonjek
    New insights into placebo effect August 31st, 2012 in Other Sciences / Mathematics (Phys.org)-Mathematical models developed by scientists at the University of
    Message 1 of 2 , Sep 1, 2012

      New insights into placebo effect

      August 31st, 2012 in Other Sciences / Mathematics
      New insights into placebo effect (Phys.org)—Mathematical models developed by scientists at the University of Bristol are providing new insights into why the placebo effect exists and when it should occur. Their research is published today in the journal of Evolution and Human Behaviour.

      A placebo – such as a sugar pill – is a treatment which is not effective through its direct action on the body but works because of its effect on the patient's beliefs.  But if individuals are capable of recovering without external aid, why do they rely on an external cue?  In other words, why have individuals not evolved the ability to get better immediately on their own?

      Members of the Modelling Animal Decisions group in the University of Bristol's School of Biological Sciences built mathematical models of the placebo effect which examine the trade-off between the costs and benefits of an immune response when faced with a health problem.

      The work is based on an idea proposed by the theoretical psychologist Professor Nicholas Humphrey.  He proposed that, as it can be beneficial to hold the immune system back from full operation due to uncertainties about the state of the world (such as the possibility of starvation), cues which indicate a change can therefore lead to an altered level of immune response.

      The models take this argument even further and demonstrate that the placebo effect is modulated by the patient's expectations.  Previous studies measuring brain activity using functional magnetic resonance imaging (fMRI) provide experimental evidence which support the models, by showing correlations between the placebo effect and regions of the brain associated with expectation.

      The models show why changes to the perceived cost of getting well, the value of being well or external environmental factors can induce the placebo effect.

      Dr Pete Trimmer, lead author of the work, said: "The placebo effect comes down to expectations about when to take action.  Waiting for a useless pill before taking action is not optimal.  But the general responsiveness to cues is adaptive, so it is logical for evolved organisms to display the placebo effect."

      The models indicate that under stress it can be better for the immune system to work less effectively.  However, the most important finding of the research is that the particular type of belief in the treatment can lead to positive or negative effects.  The belief that a treatment will cure, without any need for the immune system to do anything, could have deleterious effects on the patient's health.

      Now that a theoretical approach has laid the foundations of understanding the placebo effect, future empirical work may provide insights as to how the placebo effect can be invoked and controlled in a clinical environment.  The Bristol study clearly shows that the focus of future placebo studies should be shifted to the type of belief patients have about their treatment rather than just whether a treatment is helpful or harmful.  A better understanding of the placebo effect may change the code of practice for health practitioners and save human lives.

      More information: 'Understanding the placebo effect from an evolutionary perspective' by Trimmer, PC, Marshall, JAR, Fromhage, L, McNamara, JM, Houston in Evolution and Human Behaviour.

      Provided by University of Bristol

      "New insights into placebo effect." August 31st, 2012. http://phys.org/news/2012-08-insights-placebo-effect.html

      Posted by
      Robert Karl Stonjek

    • Philip Benjamin
      [PhysOrg.com] The models indicate that under stress it can be better for the immune system to work less effectively. However, the most important finding of
      Message 2 of 2 , Sep 1, 2012
        [PhysOrg.com] "The models indicate that under stress it can be better for the immune system to work less effectively. However, the most important finding of the research is that the particular type of belief in the treatment can lead to positive or negative effects. The belief that a treatment will cure, without any need for the immune system to do anything, could have deleterious effects on the patient's health".
        [Philip Benjamin]
        Is there a control group with neither the placebo nor the pills? If "the belief that a treatment will cure" is all that matters then why not a group with an equally strong belief  that "no treatment of any kind will also cure"
        "The Bristol study clearly shows that the focus of future placebo studies should be shifted to the type of belief patients have about their treatment rather than just whether a treatment is helpful or harmful". "No treatment belief" is also a type of belief. There are many such "believers in natural therapy" around the globe-  Mind Cure, Faith Cure, the Prayer Cure, the Mental Science Cure, the Christian-Science Cure; the Meditation Cure, the Shaman Cure, Scientology Healing, Sufi Healing, Swami Healing, Yogi Healing, Saints Healing, Spiritualist Healing, Atheist Spiritual Perspective Healing, Satan Healing  etc. Will all these be wrapped as placebos?
         
        Best regards
        Philip
         
         
         
         

        Philip Benjamin, PhD


        http://biodarkmatter.webs.com/index.htm

        Materialism/Physicalism Extraordinaire                                                                                   Spiritual Body or Physical Spirit?


         

        To: psychiatry-research@yahoogroups.com; evolutionary-psychology@yahoogroups.com; evol_psch_news@yahoogroups.com
        From: stonjek@...
        Date: Sat, 1 Sep 2012 18:29:34 +1000
        Subject: [psychiatry-research] News: New insights into placebo effect

         

        New insights into placebo effect

        August 31st, 2012 in Other Sciences / Mathematics
        New insights into placebo effect (Phys.org)—Mathematical models developed by scientists at the University of Bristol are providing new insights into why the placebo effect exists and when it should occur. Their research is published today in the journal of Evolution and Human Behaviour.

        A placebo – such as a sugar pill – is a treatment which is not effective through its direct action on the body but works because of its effect on the patient's beliefs.  But if individuals are capable of recovering without external aid, why do they rely on an external cue?  In other words, why have individuals not evolved the ability to get better immediately on their own?
        Members of the Modelling Animal Decisions group in the University of Bristol's School of Biological Sciences built mathematical models of the placebo effect which examine the trade-off between the costs and benefits of an immune response when faced with a health problem.
        The work is based on an idea proposed by the theoretical psychologist Professor Nicholas Humphrey.  He proposed that, as it can be beneficial to hold the immune system back from full operation due to uncertainties about the state of the world (such as the possibility of starvation), cues which indicate a change can therefore lead to an altered level of immune response.
        The models take this argument even further and demonstrate that the placebo effect is modulated by the patient's expectations.  Previous studies measuring brain activity using functional magnetic resonance imaging (fMRI) provide experimental evidence which support the models, by showing correlations between the placebo effect and regions of the brain associated with expectation.
        The models show why changes to the perceived cost of getting well, the value of being well or external environmental factors can induce the placebo effect.
        Dr Pete Trimmer, lead author of the work, said: "The placebo effect comes down to expectations about when to take action.  Waiting for a useless pill before taking action is not optimal.  But the general responsiveness to cues is adaptive, so it is logical for evolved organisms to display the placebo effect."
        The models indicate that under stress it can be better for the immune system to work less effectively.  However, the most important finding of the research is that the particular type of belief in the treatment can lead to positive or negative effects.  The belief that a treatment will cure, without any need for the immune system to do anything, could have deleterious effects on the patient's health.
        Now that a theoretical approach has laid the foundations of understanding the placebo effect, future empirical work may provide insights as to how the placebo effect can be invoked and controlled in a clinical environment.  The Bristol study clearly shows that the focus of future placebo studies should be shifted to the type of belief patients have about their treatment rather than just whether a treatment is helpful or harmful.  A better understanding of the placebo effect may change the code of practice for health practitioners and save human lives.
        More information: 'Understanding the placebo effect from an evolutionary perspective' by Trimmer, PC, Marshall, JAR, Fromhage, L, McNamara, JM, Houston in Evolution and Human Behaviour.

        Provided by University of Bristol

        "New insights into placebo effect." August 31st, 2012. http://phys.org/news/2012-08-insights-placebo-effect.html
        Posted by
        Robert Karl Stonjek


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