0410 the placebo effect
TRANSCRIPT
THE PLACEBO EFFECT
Michael Putman
Quiz!
1. T/F: Placebos make patients feel better; they don’t actually get better
2. T/F: There are no negative effects of placebos
3. T/F: Placebos can reduce asthma and make wounds heal faster
4. T/F: Placebo therapy could be the end of biomedicine as we know it
5. T/F: Doctor’s can lie to patients if it is in the patient’s best interest.
Overview
I. Introduction – Placebos, Meaning, and
Misconceptions
II. Psychoneuroimmunology
III. Placebos and Anti-depressants
IV. Placebos, Doctors, and Deliberate Deception
Debate!
V. Concluding Thoughts
Documentary on the Placebo Surgeries
1:24 – 6:15
Introduction
I: Definition
The effect of a treatment that arises from a patient’s expectations and response to the treatment, excluding the treatment’s specific action
In medicine, it typically refers to a response observed after inert or inactive treatments
I: Examples of Placebos
Inert pills, drugs, or injections
Sham surgeries Inactive medical
devices Effective/non-
effective acupuncture
I: Changes in Efficacy
Specific aspects of placebo Big branded pills in high quantity work better than
smaller ones in low quantity The color of pills also matters (red vs. blue)
Type of procedures Surgery is better than injection; injection is better
than pill Previous experience
Codeine cough syrup works really well the second time
Presentation How doctor presents it / advertising / etc.
All of these relate to the meaning imparted by the treatment The biggest factor is what the person believes about it
I: Placebos Can…
Constrict the pupils, alter blood pressure, change heart rate and respiration, influence gastrointestinal secretions and peristalsis, change body temperature, produce eosinophilia and leucocytosis, enhance corticosteroid reactions, and change blood levels of creatine and lipoproteins (Perry 1981)
Negatives: Cause dry mouth, nausea, heaviness, headache, difficulty concentrating, drowsiness, sleep disturbance
I: Moerman on Placebos
Placebos do not cause anything because they’re inert
It is the psychological/emotional meaning that defines the response
This response is elicited by far more than just inert pills Must think about active agents as well
The meaning response goes well beyond psychological effects and results in physiological changes as well
II: Psychoneuroimmunology
II: Psychoneuroimmunology (PNI) Hard evidence of
the placebo effect in complex pathologies
Connections between mind, brain, and immune system
Strives to find tangible linkage between mind/body
II: PNI Foundations
Ader and Cohen suspect that immunosupression can be behaviorally induced Investigate in rat paradigm CS: saccharin US: immunosuppressant
Discovered suppression of immune system by nothing more than taste
II: Kiecolt Glaser (1999): Immune Function
Stress dysregulates NK cell activity and decreases g-interferon (IFN-g) Prospective study w/med
students Stressed students have a
suppressed immune response
Prospective study found that relaxation enhances NK activity
II: Castes, Hagel (1999): Asthma Prospective study of
children in Venezuela with asthma One group receives
psychosocialintervention (PSI)
Asthma attacks are reduced
PSI increases immune function as well Higher NK activity Higher T-cell activity Improved surface
markers
II: Kiecolt-Glaser (1995): Wound Healing
Prospective study of stress on wound healing Caregivers vs. controls Both undergo biopsy
wound Healing takes
significantly longer in controls Differences in
peripheral blood leukocytes
Placebos for Depression15:20 - 19:00 19:00 - 20:15
III: Placebos and Depression
III: Antidepressants: Brief Reminder
Serotonin system influences mood, sleep, arousal, etc. Other modulatory systems (DA,
NE) overlap in function Selective Serotonin Reuptake
Inhibitor (SSRI) Blocks clearing mechanism Increases bioavailability of
serotonin in synaptic cleft Treat depression, anxiety, and
personality disorders Very complex process: at least
15 subtypes
III: Rise in Antidepressant Therapy Depression costs $44
billion per year to US economy
Global sales in 2005 of $16.2 billion US is 66% of the market
Most commonly written script as of 2005 More than drugs for high
blood pressure, high cholesterol, or asthma
118 million scripts/year Top two in 2005 were Paxil
and Lexapro
III: The Emperor’s New Clothes Kirsch et al. 2002
Meta-analysis (47 trials) of data submitted to the FDA from 1987 to 1999 on the 6 most popular SSRI’s
Mean difference between placebo and drug was ~2 points out of 50 and 62 point scales
80% of the effect due to placebo
Authors conclude that drug effect was clinically negligible Breaking the blind?
III: The Emperor’s New Clothes 2.0 Previous results
called into question Same studies as before Included initial levels of
depression this time Conclude that there is
a slight difference for severely depressed patients This was due to a
decrease in placebo efficacy
III: How is this Possible?
File Drawer Effect Journals tend to publish
findings Unblinding of Raters
Side effects often reveal treatment group
FDA Standards Must show “safety and
efficacy” 2 placebo-controlled
trials required with positive results
III: Prozac and Suicide
Increased risk of suicide with Prozac
Oct 2004: FDA instructs SSRI makers to include black box warning Doubled risk of
suicide in adolescents July 2005: FDA issues
public health warning
III: Side Effects of SSRI’s
Anhedonia; apathy; nausea; drowsiness or somnolence; headache; clenching of teeth; extremely vivid and strange dreams; dizziness; changes in appetiteweight loss/gain; may result in a double risk of bone fractures and injuries; changes in sexual behaviour; increased feelings of depression and anxiety (which may sometimes provoke panic attacks); tremors; autonomic dysfunction including orthostatic hypotension, increased or reduced sweating; akathisia; liver or renal impairment; suicidal ideation (thoughts of suicide); Photosensitivity (increased risk of sunburn)
Sir William Osler (1849-1919) – The “Father of Modern Medicine”
“We should use new remedies quickly, while they are still efficacious”
Doctors Prescribing Placebos?
12:16 – 13:30… 14:45?
ABC News Story
IV: Physicians and the Placebo
IV: Do Doctors Prescribe Placebos? NY Times: “Half of doctors routinely prescribe
placebos” 679 internists and rheumatologists from national list Everything from vitamins and headache pills to
vitamins antibiotics and sedatives Time Magazine: “Is your Doctor Prescribing
Placebos?” 466 faculty surveyed in Chicago medical schools 45% have prescribed placebos in regular practice 96% believe placebos can have “therapeutic effects” 1/5 lied outright, claiming it was medication
This house believes that doctors should aggressively prescribe placebos if proven treatments do not exist.
IV: Debate
V: Concluding Remarks
Placebos are much more than pills They have the potential to bring about real
physiological changes Placebos are tied to meaning
Surgery is very powerful; presentation, beliefs, etc. all influence the power of individual placebos
The “Meaning Response” has real clinical application The way doctors present things changes them Prescribing fake drugs may actually work
The Problem with Placebos They only work because “real drugs” “work”
THE END Final thoughts20:15 – 20:45