The Placebo Response In Dry Needling

The placebo response is a psychobiological phenomenon we should use to good effect.

Like it or not, everything we do as physiotherapists has a placebo effect or exerts what may be referred to as ‘non specific effects’.

Whether it is manual therapy, exercise, electrotherapy or dry needling there always has been and always will be a portion of the therapeutic effect which is not necessarily specifically related to the technique itself and which relies on context, expectation, the quality of the therapeutic relationship and so on.

This is even true for surgery where the expectation of a therapeutic benefit can result in significant pain relief even if the surgery is not actually performed!

Expert opinion in this area suggest the non specific effects could account for 30-70% of the therapeutic effect depending on the treatment as well as other contextual factors.

The placebo effect is in reality a range of effects (plural) which may include:

  • An anxiolytic effect
  • Activation of the nucleus accumbens with the subsequent release of dopamine
  • Activation of the endogenous opioid analgesic system - particularly useful when treating pain
  • Other immune and neuroendocrine effects, for more detailed information, please read this very interesting (but detailed paper) titled the neurobiology of the placebo effect.

It is very important to recognize that the placebo effect is a learned response, the more often a placebo response is elicited, the more likely it will occur again!

A distinction is made been conscious and unconscious expectation eliciting either conscious or unconscious effects respectively. For example of a patient consciously expects a reduction in pain, they may be a conscious reduction in pain perception. However if an active drug is used for a number of days and then replaced with an inert, placebo drug, assuming the body at an unconscious level has learnt and now expects and therapeutic effect from the drug, the therapeutic effect has been shown to continue despite replacement with a placebo. I found this very interesting and if you do to I’d suggest taking a listen to a very interesting interview with Prof. Fabrizio Benedetti who has researched and published extensively on this topic.

What is extremely important to recognise with regards the placebo effect is that what we say to our patients, how we engage with them, how we prepare them for treatment and how we manage their expectation of treatment will have a significant effect of the treatment outcome.

In other words, over and above the specific effects your needling, manual or exercise therapy may be having, if your want to optimise the therapeutic outcome you need to optimise the non specific effects as well.

This of course needs to be done ethically and not misleading the patient. What I am talking about here is being confident in yourself and what you are doing to make a difference, believe in what you are doing and let the patient know that you would not be treating them this way if you did not expect it to work!

Referring to evidence based practice (which we should all be engaged with) may help, but I find the ‘social proof’ approach works better, telling patient that you had ‘a very good result with a very similar back problem using this approach last week’ can really help with positive expectation and with it an expectation of a good therapeutic effect.

Other important aspects of the therapeutic relationship may be caring, empathy etc although this may not be as important as we think.

At the end of the day we want the best results for our patients, in order to achieve this I believe we should be using every possible approach and technique (within reason). So next time you are talking to your patient, think about what you are saying as well as how you are saying it.

Otherwise the risk of negative expectation is the NOCEBO effect - if a patient does not expect to get better they won't and if the treatment is perceived to be potentially harmful this could also have an adverse effect. This of course raises a possible discussion about discussing precautions and contraindications, but that's for another article!

by Simon.

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