Dipartimento di Neuroscienze, Università degli Studi di Torino
e
Istituto Nazionale di Neuroscienze (INN), Torino
www.personalweb.unito.it / fabrizio.benedetti
www.ist-nazionale-neuroscienze.unito.it
Placebo
Improvement
Spontaneous
remission
Biases
Regression to
the mean
Unidentified
co-interventions
Psychosocialpsychobiological
factors
Detection
ambiguity
Expectation
Pavlovian
conditioning
Reward
mechanisms
Anxiety
mechanisms
Placebo effect = Context effect
Dummy
Medical treatment
treatment
Conscious
Unconscious
Conditioned
response
COGNITION
• Expectation
• Belief
• Trust
• Hope
Effect
Conditioned
stimulus
Therapeutic Negative
effects
effects
Benedetti (2008) Ann Rev Pharmacol Toxicol 48: 33-60
Psychosocial context
expectation
and/or conditioning
Immune
responses
IFN-g, IL-2
5-HT1B-1D
Analgesia and
Parkinson
Analgesia and
respiratory
Hormonal
cardiovascular
centers
responses Depression
system
?
?
Hyperalgesia
5-HT re-uptake
immuno
sumatriptan
anti
suppressive
depressant
D2-D3
CCK-A/B
m-opioid
anti
CCK
narcotic
parkinsonian antagonist
Drugs
Benedetti (2008) Annu Rev Pharmacol Toxicol 48: 33-60
b-adrenergic
b-blocker
Benedetti et al. (1995) Lancet 346: 1231
Benedetti et al. (1995) Lancet 346: 1231
computer
Open injection
BUPRENORPHINE
open
hidden
Hidden injection
TRAMADOL
open
hidden
KETOROLAC
open
hidden
METAMIZOL
open
hidden
Pain reduction
0
-1
Pharmacodynamic
effect
Psychological
effect
-2
-3
Benedetti et al (1995) Lancet 346: 1231
Amanzio et al. (2001) Pain 90:205-15
Colloca et al (2004) Lancet Neurol. 3: 679-684
TRIAL Met#2
(Colloca and Benedetti, Nature Rev Neurosci 6: 545-552, 2005)
Is metamizol (300 mg) effective in post-thymectomy pain?
Open metamizol injection group (N=10)
Hidden metamizol injection group (N=10)
Informed consent “You will receive metamizol but you don’t know when”
Double blind
10
Open injection of metamizol
Pain intensity (NRS)
8
6
4
2
0
10
Hidden injection of metamizol
Pain intensity (NRS)
8
6
4
2
0
0
1
2
3
4
5
6
hours
Dipartimento di Neuroscienze, Università degli Studi di Torino
e
Istituto Nazionale di Neuroscienze (INN), Torino
NEUROFISIOLOGIA
CHIRURGIA
Antonella Pollo
Luana Colloca
Sergio Vighetti
Giuliano Maggi
Caterina Casadio
Anna Arslanian
PSICOLOGIA
Martina Amanzio
Claudia Arduino
Elisa Carlino
NEUROLOGIA
Leonardo Lopiano
Innocenzo Rainero
Giovanni Asteggiano
www.personalweb.unito.it / fabrizio.benedetti
www.ist-nazionale-neuroscienze.unito.it
NEUROCHIRURGIA
Michele Lanotte
Antonio Melcarne