The placebo effect Flashcards
What makes up the placebo response?
Contexual factors: Positive mood of practice. Effect of going to doctor etc.
Environmental factors: Improvement was going to happen anyway and the treatment did nothing.
What are the characteristics of placebo?
Coloured pills work better than white pills.
Larger pills better than smaller pills.
Who can be affected by placebo?
Magnitude of placebo response affected by contextual factors
Anyone can respond to placebo
We cannot predict who will respond.
It is not consistent or repeatable
How effective is placebo analgesia?
Placebo often decreases VAS by 2 to 3 points
56% as effective as morphine
How does placebo analgesia work?
Interactions between endogenous opioid system and polypeptide cholecystokinin
Dopaminergic reward system activation.
What is the difference between placebo and nocebo effect?
The difference between placebo and nocebo is in the response to the inert therapy. A beneficial response to an inert substance is a placebo response; a side effect to an inert substance is a nocebo response
How can the placebo effect be optimised?
Work with expectation
Use empathy and cooperation
Use previous experience and learning (effect of conditioning)
Enhance knowledge and avoid symptom worsening (tell patients about how they will improve)
New innovative treatment
Looks powerful
According to patient’s belief.
Positive patient expectations.
