The Placebo Effect Flashcards
What does placebo mean?
To please
What is the placebo effect?
A real therapeutic effect induced by a substance or treatment with no demonstrable active therapeutic effect
What factors affect pain perception?
Cognitive
Education/beliefs
Sensitisation
Emotion/mood
Chemical or structural
Genetics
What can affect the strength of the placebo effect?
Motivation and expectation that it will work
What is classical conditioning?
Acquisition
- Injection of drug/substance with a positive or negative taste experience
Evocation
- Replication of original taste experience reproduces the drugs effects without actual injection of the drug
What are the 3 potential pathways affected when using classical conditioning?
Pro-inflammatory cytokines
CNS cytokines
Adrenergic sympathetic transmission
How do emotions alter the experience of pain?
Cognitive and emotional mechanisms influence pain experiences via prefrontal-limbic-brain stem interactions
What does nocebo mean?
When negative expectations of the patient regarding treatment cause the treatment to have a more negative effect than it would otherwise
What are the key placebo receptors?
Mu opioid
D2 and D3 dopamine
What are the key nocebo receptors?
CCK-A
CCK-B
And decreased binding at placebo receptors
Can anything block the placebo effect?
Naloxone
How does expectancy affect the placebo effect?
Associated with dopamine mediated expectancy reward system
Stronger placebo response with strong response to monetary rewards
How does motivation affect the placebo effect?
Stronger placebo effects with more invasive treatments
What effects do conditioning have on the placebo effect?
Prior exposure and associations, largely unconscious
What is the gold standard for trials in human studies?
Double blind randomised placebo controlled trials
