Week 8: Psychology of Treatment & Placebos

What is the placebo effect?

a beneficial health outcome resulting from a person’s anticipation that an intervention (pill, procedure, injection) will help them. A clinician’s style in interacting with patients may also bring about a positive response that is independent of any specific treatment.

What is the nocebo effect?

a detrimental health outcome resulting from a person’s anticipation that an intervention (pill, procedure, injection) will harm them. A clinician’s style in interacting with patients also may bring about a negative response that is independent of any specific treatment.

What is the difference between placebo/nocebo effect and placebo/nocebo response?

Effect: effects are tare attributed just to the patient’s reaction to a specific intervention (so nothing else from the experience (ie; clinical environment)

Response: both the placebo/nocebo effect + other influential factors (ie; clinical environment, expectations, etc.)

• expectations

• conditioning

• relationships

• environment

  These are all components of the Placebo/Nocebo Effect or Placebo/Nocebo Response?

Placebo/Nocebo Response

• pill

• injection

• acupuncture

• surgery

  These are all components of the Placebo/Nocebo Effect or Placebo/Nocebo Response?

Placebo Nocebo Effect

Name the factors in the Placebo-Nocebo Effect?

• invasiveness of the procedure

• feature associations

• expense

• classical conditioning (prior and experimental)

True/False

The more invasive an intervention is the smaller the placebo effect.

False

the more invasive an intervention is the bigger the placebo effect

True/False

Placebo effects are larger when using a pill rather than a capsule

False

it’ll be a larger effect when using a capsule

Feature association influence that Placebo-Nocebo effect or response?

Effect

Expense of an intervention influence the Placebo/Nocebo effect or response?

Effect

Classical conditioning influences Placebo-Nocebo effect or response?

Both

Expectancy influences the Placebo-Nocebo effect or response?

Response

Changes in thoughts, emotions, behaviors influence the Placebo-Nocebo effect or response?

Response

Personality of the patient/client influences the Placebo-Nocebo effect or response?

Respone

Patient-provider relationship influences the Placebo-Nocebo effect or response?

Response

The clinical environment influences the Placebo-Nocebo effect or response?

Response

The social environment influences the Placebo-Nocebo effect or response?

Response

What are the types of placebo study designs?

• double blind study

• 3 arm or 2 arm

  • 2 arm: treatment v. placebo

  • 3 arm: treatment v. placebo v. no treatment (waitlist)

• 4 arm studies?

  • treatment v. placebo v. no treatment with clinical interactions v. no treatment without clinical interactions

Describe the 2 arm study design for placebo/nocebo studies

• treatment v. placebo

• Henry Beecher

• these types of studies are usually to understand the placebo/nocebo responses (not interested in treatment)

Describe the 3 arm study design for placebo/nocebo studies

• treatment v. placebo. v. no treatment (waitlist)

Describe the 4 arm design

• treatment v. placebo v. no treatment with clinical interactions v. no treatment without clinical interactions

• this way the placebo responses can be more thoroughly separated from pure treatment effects

Describe the Double-blind study design

• some get real treatment, some get placebo

• neither participant nor researchers know who’s getting what

• can be hard to keep blinded for invasive treatments

What is perceptual bias?

participants perceiving their symptoms more readily because they’re paying closer attention to their bodies (anticipating changes cause they’re taking treatments or are being asked to record symptoms)

What is response bias?

patient report symptoms differently even though the symptoms have not really changed (ie; due to social desirability, behaving in ways thought to be desired by others)

What is the Hawthorne effect?

changes in behavior because they are being observed

what is publication bias?

studies with positive results are more readily published that studies with small or null effects

What are some issues in placebo studies?

• spontaneous remission

• regression to the mean

• concomitant treatments

• drop out rate

• inadequate blinding

What is spontaneous remission?

patient gets better on their own

What is regression to the mean?

patient’s symptoms don’t remain constant (improve, worsen - changes in extremes)

What is concomitant treatments?

no treatment (waitlist) group getting treatment from another study

In which group are drop out rates highest?

• placebo

• treatment

• no treatment

no treatment

What is inadequate blinding?

participants being able to figure out if they’re getting the real treatment or placebo

What is placebo controlled drug reduction?

when the treatment and placebo are both powerful (treatment higher), and the treatment has some negative side effects, then you can use the placebo for a portion of the treatment

When the treatment is powerful and the placebo is weak, which should you emphasize?

treatment

If the treatment is weak and the placebo is powerful, which should you emphasize?

ethical concerns….if you use treatment (pay money and all that for it) when placebo can give same response…

What are the 2 neurobiological systems affect Placebo/Nocebo responses?

pain

movement (motor control)

Analgesia is

pain releif

Hyperalgesia is

increased pain perception

What pathways are triggered by the prefrontal activity of expectations of a placebo?

• release of endorphins which triggers periaqueductal gray area (PAG area) which quiet the pain signals

• release of dopamine trigger nucleus accumbens which is the pleasure/reward pathway

What does the PAG (periaqueductal gray area) do?

quiets pain signals coming up the brain from other parts of the body

What does the nucleus accumbens do?

pleasure pathway, rewards

When someone expects increased pain from a nocebo what pathways are triggered and what happens?

• dopamine pathway quiets, so no stimulation of the brain reward center

• cholecystokinin (CCK) which triggers PAG area and heightens pain signs

How have the involvement of endorphins in expectations about a placebo been confirmed?

When given the endorphin blocking agent Naloxone, the placebo effect stops (so you’ll continue to receive pain

• shows that the placebo effect does trigger pain pathway and makes pain stop like an analgesic would

How have the involvement of CKK in expectations about a nocebo been confirmed?

CCK blocking agent: Proglumide was given and the nocebo effect stopped (so people stopped experiencing pain)

In the Dental Study (given either morphine, saline, something that would increase pain — and told which they were getting) when given saline did participants report a reduction or increase in pain?

reduction in pain

In the Dental study, when saline participants were given the endorphin blocker Naloxone did they report an increase, decrease, or same amount of pain?

Increase in pain (so placebo effect was reduced)

A warm, empathetic provider is more/less likely to contribute to a placebo response

more

A cold, distant provider is more/less likely to contribute to a placebo response

less

The patient provider relationship does not affect the placebo/nocebo response True/False

False, it does affect the placebo/nocebo response

If the provider shows enthusiasm for benefits of treatments, this shapes the patients expectations of the placebo/nocebo response (select one)

placebo response

If the provider seems uncertain and emphasizes the side effects of the treatment, this is more likely to move expectations of a patient to placebo/nocebo response (select one)

nocebo

The patient’s expectations has no impact on their placebo/nocebo response true/false

false

What is pure placebo

Placebo treatment considered to have no known medical effect (ie; sugar pills, saline injections)

What is an impure placebo

An active treatment for something but not the condition for which it is given (ie; antibiotic being given for a viral infection)

_____% of American doctors use placebo

1. 25%

2. 75%

3. 45%

45%

True/False

97% of English doctors use impure placebo

true