The placebo effect Flashcards
(12 cards)
Describe the placebo effect
A person’s physical or mental health appears to improve after receiving a treatment with no therapeutic value.
Describe a placebo treatment
A substance or therapy lacking active pharmacological effect, yet still produces symptom relief.
What are the key characteristics of placebo treatments
Do not cure diseases.
Are most effective for subjective symptoms:
Pain
Stress-related insomnia
Cancer treatment side effects (fatigue, nausea)
What are the psychological consequences of chronic pain
Chronic pain is often maladaptive, serving no protective function.
Psychological consequences:
Mood disturbances
Catastrophizing vs distraction
Cognitive impairments
Alterations in brain structure/function
Ineffective coping strategies can exacerbate symptoms.
What are the two components of the treatment response
Drug Effect – biological/chemical action.
Placebo Effect – response not attributable to drug:
Natural course of illness
Regression to the mean
Expectations and psychological context
What factors influence the placebo effect
- Patient Characteristics
Some individuals are more susceptible.
Children often show a higher placebo response.
- Health Professional Characteristics
Higher perceived status, empathy, and confidence increase placebo effect. - Treatment Characteristics
Form of placebo matters:
Placebo morphine > placebo aspirin
Branded analgesics > generic ones
Injection > oral pill
Colour effects:
Blue pills = depressant effect
Red pills = stimulant/analgesic
Higher dose = stronger response
Is there a biological basis of the placebo
Brain imaging shows neurobiological responses to placebo.
Not just “all in the mind” – real physiological changes.
What is the proposed mechanism of action
Learned response: conditioning over time.
Interaction of:
Internal factors (patient expectations, beliefs)
External factors (context, healthcare environment)
Involves:
Anxiety reduction
Cognitive dissonance
Release of endogenous opioids
Neurochemical changes (dopamine, endorphins)
What are the negative consequences of the placebo effect
Experience of side effects after inert treatment.
Often driven by anticipation, suggestion, or anxiety.
E.g., developing a headache after hearing it’s a common side effect.
How have placebos been used in clinical practice
2008 survey: 97% of UK GPs have used a placebo.
Placebos used are often impure (have therapeutic properties in other contexts).
Examples:
Antibiotics for viral infections
Vitamins for fatigue without deficiency
What ethical considerations must be considered when using placebo
Deception raises ethical issues.
Must balance benefit vs consent.
Transparency is key in modern healthcare.
How are placebos used in clinical research
Central to placebo-controlled trials:
Compare placebo to no treatment = isolates placebo effect.
Compare active drug to placebo = isolates drug effect.
Gold standard in assessing drug efficacy.
