Placebo Effect

Factors that affect the placebo effect

Placebo effect

Beneficial response to a treatment that doesn't contain any active substance

Brainwaite + Cooper (1981) - Type of Pill

Branded pills reduce pain more than generic pills

De Craen et al (1996) - Colour

Red/Yellow - associated with stimulant effect - less effective in pain reduction
Blue/Green - associated with tranquilising effect - more effective in pain reduction

Amanzio et al (2001) - Who Administers Placebo

More pain relief when doctor administers placebo in comparison to a machine

Price et al (1999) - Expectancy

Participants were given placebo cream to give administered painful heat stimulant
Pain was highest in those who were told it was a placebo, and lowest in those told it was a strong pain killer

Kaptchuk et al (2014) - Expectancy

Patients with migraines received a placebo or pain relief and told what they received
Reduction of pain in both conditions

Bingel et al (2011) - Expectation

Administered painful heat simulation, 0 (no pain) to 100 (unbearable pain)
Condition 1 – Baseline (saline) – pain rating 66
Condition 2 – No expectation (received painkillers but told it was saline) – pain rating 55
Condition 3 – Positive expectation (Received painkillers and told it was painkillers) – pain rating 39
Condition 4 – Negative expectation (received painkillers, told they weren’t painkillers) – pain rating 64

Ethical Issues

Deception