Placebo Effect 1

Question 1

Placebo Effect

Answer 1

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

Question 2

3 things that are mistaken placebo effects?

Answer 2

1. Natural time course: spontaneous recovery / regression to the mean (go when you feel the worst and you are likely to get better anyway) 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 (change scale to report a symptom)
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.

When you expect something this has neurological substrengths

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.

Question 4

Example of Kirsch’s expectancy theory

Answer 4

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 5

Classical conditioning and the placebo effect

Wickramasekera

Answer 5

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).

Placebo effect was a conditioned response, repeated context plus drug acquires conditioned response

Question 6

Example of placebo effect and classical conditioning

Answer 6

Many trips to the hospital, you may associate the hospital with reduced pain (and you may feeling reduced pain without even receiving treatment

Question 7

nocebo effects vs placebo effects

Answer 7

negative expectancies vs positive expectancies and outcomes

Question 8

Issues with placebo vs nocebo definition (4)

Answer 8

1. positive and negative effects simultaneously
2. Who defines positive vs negative
3. What about neutral effect? (growth)
4. How well can we access people’s expectancies

Question 9

Placebo in terms of substances

Answer 9

inert (not doing anything) vs active (mimic side effects of actual treatments)

Question 10

Placebo in terms of procedures

Answer 10

could have surgery or acupuncture (not actually penetrating skin)

Question 11

What is placebo psychotherapy?

Answer 11

Simply talking i.e. without reliance on techniques underlying psychotherapy

Question 12

Colaguiri Sleep placebo pill experiment showed ..

Answer 12

Any reduction is above and beyond that could have been expected with no treatment - use controls

Question 13

Amanzio and Benedetti (1999)

Answer 13

How suggestion influences placebo

Pain test, squeeze grip - causes constriction and pain

Higher scores mean more tolerance to pain

Placebo leads to increased pain tolerance

Reversal of placebo effect when given naloxone implicates the role of endogenous opioids release

Question 14

Placebo effect vs placebo response

Answer 14

The response to placebo is placebo response, the effect itself is the specific component of the expectancy to get better than makes get better

Pure effect of expectancies

Question 15

Benedetti et al (2003) Open vs hidden treatment

Answer 15

Either knowing they are getting given morphine or not

Even though the dose is the same, pain report differs whereby

Open morphine produces more analgesia than hidden morphine, i.e. when there is expectancy

When you turn off morphine and tell them this leads to greater increase in pain i.e. when expectancy is removed

Same seen, effects of drugs being better when knowing you are taking it

Question 16

Parkinson’s disease placebo effects treatment (open vs hidden)

Answer 16

Motor performance improvements as a result of subthalmic stimulation in patients with parkinson’s disease (when knowing)

Question 17

relationship between conditioning instruction expectancy and PE

Answer 17

instruction leads to expectancy - PE
Conditioning leads to expectancy - PE

unclear whether conditioning without expectancy can led to PE

Question 18

Amanzio and Benedetti - How placebo effects are formed

Answer 18

placebo injection reduces pain even when there is no expectancy for pain relief

Get rid of expectancy by saying it is another drug doing effect

Reversal again points to the role of endogenous opiods