Lecture 23 & 24 - Placebo Effect

Question 1

Placebo effect

Answer 1

A genuine physio/psychological response that is not attributable to the actual treatment

Question 2

Things that are mistaken placebo effects?

Answer 2

1. Natural time course: spontaneous recovery / regression to the mean where effects decline/increase due to natural course of illnesses, mental disorders
2. Reporting bias: demand characteristics (respond in a way we think the reporter wants) or criterion/response shift
3. Behavioural change such as the Hawthorne effect (act of being observed changes behaviour, not the actual treatment)

Question 3

Kirsch’s expectancy theory

Answer 3

Suggestion and experience create response expectancies and these responses expectancies can produce placebo effects in and of themselves; the placebo elicits an expectation for a particular effect, and the expectation produces that effect.

The occurrence of a PE reinforces the expectancy on which the PE is based on, i.e. it is self-fulfilling. There is no extinction of PE.

E.g. having a panic attack before an exam, you expect to have one before the next exam and then you stress about the panic attack etc. etc.

Question 4

Classical conditioning and the placebo effect

Answer 4

Placebo effect occurs when after repeated context CS -> US (context-drug) pairing, the CS (context) acquires the ability to elicit a CR (drug response, e.g. high).

E.g. many trips to the hospital, you may associate the hospital with reduced pain (and you may feeling reduced pain without even receiving treatment)