• Question: Why does the placebo effect work?

    Asked by grago to Ben, Dave, Ed, Sam, Susana on 24 Jun 2013.
    • Photo: Benjamin Hall

      Benjamin Hall answered on 24 Jun 2013:


      Deception.

      The patient is told that they will get better when prescribed the placebo treatment, the patient expects to get better so the patient feels better. However, it doesn’t work for everything. For example, a placebo effect has never been observed for things a doctor can easily measure, like blood pressure. It only works for symptoms a patient must self-report like pain levels or feeling depressed. This tells us the placebo effect is mental, rather than physical.

    • Photo: David Briggs

      David Briggs answered on 24 Jun 2013:


      Great question – the placebo effect is basically the non-physiological effect caused by any sort of medical treatment.

      Your body has the ability to heal itself, or to release it’s own built in pain killers, like endorphins. Even by sitting down and talking to a doctor or nurse, or doing something that makes you feel better can trigger release these endorphins.

      A great example of the placebo effect is homeopathic medicine – homeopathic medicines are diluted to the point where they contain nothing but water, which is then dropped onto a little sugar pill – how can a little sugar pill cure you of anything? Answer – it can’t!

      But it might make you feel better – if you believe that the little sugar pill works, and if you are suffering with something fairly trivial, like a headache, your belief that you have done something positive to fix your headache can induce your brain to release endorphins – therefore you magically feel better – and you mistakenly believe that it was the homeopathic remedy that made you better, when in fact it was your own endorphins.

      Did you know that there is a flip-side to the placebo effect – called the nocebo effect? You can actually trick yourself into feeling worse – a great example (found in Ben Goldacre’s book “Bad Science” I think) surrounds people thinking that mobile phone signals can make you sick.

      In South Africa, a mobile phone company wanted to build a phone mast in a town – the town people wrongly thought that the mobile phone signals would make them ill, and they protested about this – but the council gave the company permission to build the mast. As soon as the mast was built, the town people started complaining of a strange illness, headaches, aches and pains – things like that. They all said that the phone mast had made them ill, and tried to get the council to take it down.

      The council ask the phone company what was going on, and they came back and told the towns people that they hadn’t even turned the mast on yet – so all their ache and pains were all in their mind – they had suffered from the nocebo effect – the bodies ability to (sometimes) make yourself ill!

    • Photo: Sam Horrell

      Sam Horrell answered on 24 Jun 2013:


      There’s not much I can really add to those answers. It just shows how powerful the brain really is.

    • Photo: Ed Lowe

      Ed Lowe answered on 24 Jun 2013:


      Essentially, exactly what Ben and Dave have said.

      It’s the effect that makes you feel better when as a small child your Mum pampers you a bit after you’ve fallen over and grazed yourself. Nothing more than a few kind words but you feel a lot better.

      I like that example because, I think, it shows how the placebo effect can be broadly beneficial without dignifying homeopathy with even more attention than it already gets 🙂

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