Placebo Effect

What influences the placebo effect?

- BEHAVIOR OF THE HEALTH CARE PROVIDER confidence and warmth on the part of the doctor • if you have a doctor who believes a certain treatment is really good, the patient will latch onto that belief, especially if trusts the provider as a person and doctor. • Feldman study: patients given a tranquilizer by a doctor: - CHARACTERISTICS OF THE PATIENT believing that it will work • Patient's specific beliefs in the treatment itself and expectations of the outcome (I believe this thing will work and I have clear expectations of what will happen if it is working- this will guide the placebo in creating that outcome) • Need to be aware of a placebo: if drank a sugar pill and didn't know what it was intended to do as a placebo, there would be no effects. So first you need: awareness, beliefs and expectations of belief - SITUATIONAL FACTORS/CHARACTERISTICS OF THE PLACEBO (more medical seeming/more effective) NOT ALL PLACEBOS ARE EQUAL; the color, price, brand of the pill and the number of pills taken; in one study, people solved more puzzles if given an "expensive" energy drink as opposed to a discounted one (same in both conditions) • Good adherence to taking drugs make people die less; even if pill placebo • Can get addicted to placebos • Placebos don't work from place to place • Our minds create the medicine • Size of the pill how many you take, capsule versus pill vs. syringe, location matters - CULTURAL BELIEFS helped more germans than brazilians because of belief in modern medicine stronger placebo effect in cultures that have MORE faith in Western medicine

What makes a sick person get better?

- illness runs its course your body naturally fights it (natural history effect) - specific active component of a treatment • Ex: If have flu and take Theraflu, antibiotics - non-specific effects of a treatment (rely heavily on beliefs and expectations of patients)(placebo effect)

How do we test if a medication is more effective than a placebo?

- placebo controlled double blind study blind (the researcher and the people in the study don't know which group they are in) studies (finds out whether the placebo has unintended consequences) • Randomized to condition: • Active drug • Placebo • Both look exactly the same • No treatment (often wait-list)- told that can't get the drug go on waitlist to see if nothing does anything • Double-blind- the experimenter doesn't know why people are going to be on the waitlist? • Argument is that whatever outcomes comes out is Outcome measured objectively; know after this if it's the belief of the drug, the actual drug, or not associated with the drug

How do placebos work?

-Do they decrease anxiety/improve mood? has possibility of fixing upset stomach/diahrea but these are the only things it does if tell them decrease anxiety medicine DON'T DECREASE THINGS THROUGHOUT ENTIRE BODY (that would be global effect) NOT much evidence that placebos work by improving mood; evidence AGAINST placebos working by improving mood: placebos can have local effects (ex: providing pain relief ONLY in the finger given a placebo painkiller) rather than global effects - Do they contribute to endorphin release? global vs. local effect may play a role in pain, but there are many other types of placebos besides placebo painkillers • endorphins are chemicals released by brain that help reduce pain sensitivity at the moment of injury; tend to fade • but sham surgery doesn't always involve endorphin release as the mode of the placebo effect - Do they work through classical conditioning? problem with this explanation: placebos can do the opposite of what they are supposed to do • Ipecac, a drug that makes you vomit, can lead to LESS nausea o the experimenters told the people that it would make them less nauseas and it did; the drug itself has chemistry that does not abide by the chemistry in your stomach o morphine increased people's pain when told it would - Do they work by changing people's expectations? THIS IS THE BEST EXPLANATION: there is NO cases of a placebo effect in the absence of expectation • support: • you don't need prior experience with the drug, just need to be told that it will do something for you • the more believable the placebo, the more likely it is to work • a placebo can do the opposite of the active drug • there are no cases of placebo effects in the absence of an expectation • there is always expectation of the outcome of whatever is being studied because you need to know that you are being given something that has an outcome

Nocebo

an inert subject that makes someone feel worse *nocebo can --> hairless, nausea, MED STUDENT SYNDROME

What is a placebo?

any medical procedure that produces an effect because of its therapeutic INTENT, not its specific nature Most common: a sugar pill It can work! If he gave you a lactose intolerant pill and say it will make you happy all day you probably will stay happy if you believe him

Moseley et. al 2002

arthroscopic knee surgery no more effective than placebo surgery same effect as would see with acupuncture