PSYC20006 Lecture Notes - Lecture 17: Suggestion, Nocebo, Selective Serotonin Reuptake Inhibitor
12 Jun 2018
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Lecture 17 - Thursday 4 May 2017
PSYC20006 - BIOLOGICAL PSYCHOLOGY
LECTURE 17
PLACEBO: BELIEF & THE BRAIN
PHYSICAL & EMOTIONAL PAIN
•Physical pain is a psychological experience based on changes to biological states.
•Emotional symptoms involve complex brain responses and thought patterns.
•Pain is a complex biological stream of events; it is not simply psychological.
PLACEBO
•Placebo: Beneficial effects attributable to the brain/mind responses to context of treatment (drug
or device) delivery rather than its direct action.
•Pain relief
•Reduced distress
•Other symptom relief
•Nocebo: Negative effects attributable to the brain/mind responses to context of treatment
delivery rather than drug action.
•Pain
•Nausea
•Distress
•The placebo intervention (the
treatment context) is actively
interpreted by the brain and
can elicit expectations,
memories and emotions..
which can lead to symptom
improvement.
•Many treatments where the
active treatment causes
discomfort but the end result
is good.
•Often when people on placebos are told they might have side effects (nausea etc) they actually
experience them.
PLACEBO IN MEDICINE
•Placebo interventions do not - by definition - have therapeutic effects... BUT placebo effects DO
have therapeutic benefits.
•Placebo effects can be as large or larger than accepted drug treatments and can reduce disability
and increase quality of life over a period of months or longer (even reduce mortality).
•Often people that show the largest drug effects also show largest placebo effects.
•Only in recent years has placebo been investigated and interested in.
•Laboratory evidence of placebo effects on health-relevant behavioural, autonomic, endocrine and
immune measures based on verbal suggestion alone:
•From the medical perspective it is extremely important to disentangle placebo effects from the
primary intervention:
•1) to develop the best treatments
•2) to understand the actual effects of the intervention
Lecture 17 - Thursday 4 May 2017
PSYC20006 - BIOLOGICAL PSYCHOLOGY
PLACEBO NEUROSCIENCE
•From the perspective of neuroscience it is important to disentangle placebo effects from the
primary intervention to
•1) Identify brain processes that give rise to pain and other clinical symptoms (that can
themselves be targeted in future treatment)
•2) Identify functional systems engaged by placebo treatments to understand how context can
be used to influence health and well-being.
•3) Identify factors that differentiate placebo responders from non-responders (identify/predict
those likely to benefit from placebo). Some people who are very responsive to placebos are
also very responsive to treatment.
MEASURING PLACEBO
•Common ways to control & measure placebo effects in clinical studies:
•A) Parallel group design:
•3 groups, one with no treatment (or “best practice” if ethically required)
•Treatment effects = active - placebo
•Placebo effects = placebo - no treatment
•B) Open vs hidden - 2 groups:
•Treatment effects = Hidden drug
•Placebo effects = Opens drug - Hidden drug
Document Summary
Physical & emotional pain: physical pain is a psychological experience based on changes to biological states, emotional symptoms involve complex brain responses and thought patterns, pain is a complex biological stream of events; it is not simply psychological. Placebo in medicine: placebo interventions do not - by definition - have therapeutic effects Some people who are very responsive to placebos are also very responsive to treatment. Psyc20006 - biological psychology: c) conditioning design, two inactive treatments, strong verbal suggestion about 1 being active (maximizing cognitive expectancy) - verbal suggestion is reinforced with fake evidence of effect, placebo effect = difference in reported pain with equal moderate stimulus. Placebo: frontal areas are implicated in placebo effects but clearly many brain areas are involved (based on cream conditioning paradigm), amount of activation correlates with the amount of pain relief, honing in on essential prefrontal areas. Hormone responses: expectation can have real effects on the hormone responses, milkshakes on the right.
