22.Placebos.042518.pdf

22.Placebos.042518.pdf - COURSE EVALUATION NOW AVAILABLE...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: COURSE EVALUATION NOW AVAILABLE •  Complete course evalua<on h#ps://stonybrook.campuslabs.com/courseeval/ •  ≥ 80% comple<on rate –  EVERYONE gets ½ percent added to their grade •  < 80% comple<on rate –  NO ONE gets ½ percent added to their grade •  DUE DATE: December 8th EXAM 3 REVIEW •  Submit ques<ons to Top Hat by THIS Friday @ 10p •  UG TA review session in class on Monday – ARendance is op<onal Health Psychology Placebo Effects April 25, 2018 WHAT CAUSES A SICK PERSON TO GET BETTER? 1.  Natural History: –  The ailment runs its course 2.  AcHve Treatment: –  AcHve aspects of treatment (pharmacological, surgical, physical) helps the person. 3.  Placebo Effects: –  Non-specific aspects of treatment (context, delivery method, thoughts and beliefs) helps the person. WHAT IS A PLACEBO? A placebo is any medical procedure that produces an effect in a patient because of its therapeutic intent, and not because of its active qualities. HOW DO YOU TEST FOR PLACEBO EFFECTS? Test a new drug’s effect Group 1: Real drug Group 2: Placebo Shows you whether the real drug “works” because it has to be be#er than a placebo to be considered effecHve. Test a placebo effect Group 1: Placebo Group 2: No treatment Shows you whether the placebo “works” because it only has to be be#er than no treatment to be considered effecHve HOW DO YOU TEST FOR PLACEBO EFFECTS? To give the most convincing evidence for placebo effects: 1. Run a study with three groups: •  AcHve drug •  Placebo •  Nothing 2. ObjecHvely (and double-blindly) measure your outcome. SKIN RASH STUDY •  Subjects rubbed with non-poisonous leaves. •  Subjects rubbed with real poison ivy. •  Told it was real poison ivy •  Told it was nonpoisonous leaves. •  All developed a rash. •  None developed rash. 4 MORE EXAMPLES OF PLACEBO EFFECTS 1.  Placebo Rogaine 2.  Placebo acupuncture for irritable bowel syndrome PLACEBO ACUPUNCTURE FOR IRRITABLE BOWEL SYNDROME •  Sham acupuncture v wait-list control group •  Twice a week for three weeks % reporHng adequate pain relief Wait-list Subjects 28% Sham acupuncture Subjects 44% 4 MORE EXAMPLES OF PLACEBO EFFECTS 1.  Placebo Rogaine 2.  Placebo acupuncture for irritable bowel syndrome 3.  Placebo arthroscopic knee surgery for osteoarthriHs PLACEBO ARTHROSCOPIC KNEE SURGERY •  Real surgery (sedaHon + incision + surgery) •  Sham surgery (sedaHon + incision) •  Both groups –  regained ability to walk in same Hme –  2 year follow-up: 40% of those in both groups completely recovered 4 MORE EXAMPLES OF PLACEBO EFFECTS 1.  Placebo Rogaine 2.  Placebo acupuncture for irritable bowel syndrome 3.  Placebo arthroscopic knee surgery for osteoarthriHs 4.  Placebo morphine a`er dental surgery PLACEBO MORPHINE WITH DENTAL SURGERY •  IV drip of morphine •  IV drip of saline •  Both groups had high levels of pain relief! META-ANALYSIS OF PLACEBO STUDIES •  130 Studies with placebo group and control group –  Placebos work for pain –  Placebos work when outcome is measured subjecHvely and conHnuously –  Placebos work for some objecHvely measured outcomes but not all –  “Therefore placebos don’t work…” •  Conclusion? Placebos work for certain problems under certain condiHons PLACEBO TREATMENT OF ASTHMA STUDY Treatments: 1.  2.  3.  4.  Inhaler w/ albuterol (acHve drug) Inhaler w/ saline (placebo) Sham acupuncture No treatment Measures: 1.  ObjecHve (forced expiratory volume) 2.  SubjecHve (self-reported improvement) OBJECTIVE OUTCOME er Active, Inactive, or No Treatment in Asthma d trials and laboraded a no-intervena no-intervention lacebos — allowed effects. We found erventions did not ntervention control airflow was used tive outcome, both an no intervention. e effect of the pat-reported outcome 25 Change in FEV1 with Different Interventions (%) he no-intervention come, the placebo drug effect, and all vention effect. The a strong effect on ut had no effect on drug had a strong me but had no int to the subjective 20 20.1 15 P<0.001 10 5 0 Albuterol 7.5 7.3 7.1 Placebo Sham Acupuncture No-Intervention Control Figure 3. Percent Change in Maximum Forced Expiratory Volume in 1 Second (FEV1) with Each of the Four Interventions. The relative improvement in FEV1 achieved with albuterol was significantly greater than that achieved with each of the other three interventions (P<0.001). No other differences among the four experimental conditions were significant. T bars indicate standard errors. SUBJECTIVE OUTCOME The Subjective Improvement after Different Interventions (%) 60 50 n e w e ng l a n d j o u r na l P<0.001 50 45 40 46 30 20 21 10 0 Albuterol Placebo Sham Acupuncture No-Intervention Control Figure 4. Percent Change in Subjective Improvement with Each of the Four Interventions. The relative improvement in subjective outcomes, assessed with the use of a visual-analogue scale (with 0 indicating no improvement and 10 indicating complete improvement), was significantly greater with the albuterol inhaler, placebo inhaler, and sham acupuncture interventions than with the no-intervention control (P<0.001). No other differences among the four ex- of m e dic i port recent systema involved specific con cebo effects are prim outcomes; when ob tend to be well with history of the condit ings do not contrad showing that placebo changes in neurotra cific brain activity th bifurcation of place and subjective outco pilot study may repr cial scientists make jective physiology) an perceptions).22,23 Alt target and modulate the mere ritual of tr self-monitoring and disease.24 Our subjective m Since there were no LOTS OF DISORDERS SHOW PLACEBO EFFECTS •  •  •  •  •  •  •  •  •  Allergies Anxiety/Panic Disorders Asthma Bipolar/Depression Cough Crohn’s Disease/ColiHs Epilepsy ErecHle DysfuncHon Herpes •  •  •  •  •  •  •  •  •  Hypertension Irritable Bowel Migraine MulHple Sclerosis Nausea Pain PMS Reflux Ulcers DISORDERS WHERE I HAVE NOT HEARD OF PLACEBO EFFECTS •  •  •  •  Cancer treatment HIV Dialysis for kidney disease Blindness or deafness BUT… do help with side effects from treatment WHAT DETERMINES IF PLACEBOS WORK? 1. How the health-care provider behaves 2. CharacterisHcs of the paHent 3. SituaHonal factors 4. Social norms PROVIDER BEHAVIOR MATTERS 1.  PaHents given tranquilizer by doctor who expressed: –  Confidence –  Doubt 77% 10% % EffecHve 2.  PaHents with irritable bowel syndrome given: –  Nothing 28% –  Sham acupuncture 44% –  Sham acupuncture with a warm and posiHve doctor 62% % ReporHng Improvement WHAT DETERMINES IF PLACEBOS WORK? 1. How the health-care provider behaves 2.  Characteris<cs of the pa<ent 3. SituaHonal factors 4. Social norms PLACEBO-PRONE PERSONALITY Placebo Responder WHAT DETERMINES IF PLACEBOS WORK? 1. How the health-care provider behaves 2. CharacterisHcs of the paHent 3.  Situa<onal factors 4. Social norms SITUATIONAL FACTORS •  •  •  •  •  •  •  •  •  PosiHve NegaHve prior experience High Low expectaHons Medical senngs Non-medical Complicated instrucHons Simple instrucHons Rx Drugs Rx Behavior change Expensive pill Pill on sale Surgery InjecHons Capsules Tablets Yucky tasHng pills Good tasHng pills Pill Color Ma#ers! Cool colors: Tranquilizing or sedaHng Hot colors: SHmulaHng WHAT DETERMINES IF PLACEBOS WORK? 1. How the health-care provider behaves 2.CharacterisHcs of the paHent 3. SituaHonal factors 4.  Social norms SOCIAL NORMS 59% 7% HOW DO PLACEBOS WORK? •  Decrease anxiety –  Reduce physical symptoms of stress •  Upset stomach •  Diarrhea •  Trouble sleeping –  Not all placebo effects have to do with these things HOW DO PLACEBOS WORK? •  Decrease anxiety •  Endorphin release –  Endogenous opioids naturally produced by the body •  When you give someone a placebo, their body releases endorphins, which relieve your pain. –  Not all placebo effects have to do with pain BRAIN IMAGING OF PLACEBO EFFECT Baseline: Brain imaging without inducing pain Pain: Induce sustained pain with jaw injecHon Pain plus placebo: Added an injecHon of a placebo pain reliever Results: Placebo responders had increased acHvity in opioid receptors HOW DO PLACEBOS WORK? •  Decrease anxiety •  Endorphin release •  Classical condiHoning CONDITIONED PAIN RELIEF •  Before Conditioning Needle Morphine No response Pain reduction •  During Conditioning Needle + Morphine Pain reduction •  After Conditioning Needle Pain reduction PROBLEMS WITH CONDITIONING ARGUMENT 1.  Placebo effects can get stronger over time, but conditioned effects show extinction 2.  Placebos can do the opposite of what active treatment is supposed to do 3.  Placebos behave in culturally determined ways HOW DO PLACEBOS WORK? •  Decrease anxiety •  Endorphin release •  Classical condiHoning •  ExpectaHons SUPPORT FOR EXPECTATION ARGUMENT •  Prior experience with the drug is not necessary •  The more believable the placebo, the more likely it is to work SUPPORT FOR EXPECTATION ARGUMENT •  Prior experience with the drug is not necessary •  The more believable the placebo, the more likely it is to work: In brain imaging study, the more that Ss expected the placebo to work, the more brain activity in their opioid receptors. •  A placebo can do the opposite of the active drug •  You don’t typically see placebo effects in the absence of an expectation PLACEBO CAFFEINE AND MOTOR TASK •  Subjects given placebo caffeine and told: – It will help – It will hurt – No informaHon •  Performance followed the suggesHon CONDITIONING AND EXPECTANCIES TOGETHER 1. Natural history No Change 2. Placebo + ExpectaHon of less pain 3. Placebo + ExpectaHon of more pain More Pain 4. CondiHoned less pain + ExpectaHon of less pain 5. CondiHoned less pain + ExpectaHon of more pain More Pain CONDITIONING AND EXPECTANCIES TOGETHER Placebo + Placebo + NOCEBO EFFECTS Just like placebo effects, but inacHve substance causes unpleasant effect –  Pain –  Hair loss –  Nausea –  Medical student syndrome –  Asthma ASTHMA STUDY Nocebo Effect •  PaHents given saline and told it would impair their breathing. ASTHMA STUDY Nocebo Effect •  PaHents given saline and told it would impair their breathing. It caused asthma a#acks. Placebo Effect •  Same paHents given saline and told it would stop their asthma a#acks. It stopped their asthma a#acks. SHOULD DOCTORS AVOID INDUCING NOCEBO EFFECTS?? •  Need to be honest about side effects •  How can you do this in a way that doesn’t induce nocebos? •  Maybe only menHon those most likely? •  A great quesHon for an ethicist… SHOULD DOCTORS PRESCRIBE PLACEBOS? •  Cheaper, safer than drugs •  PaHents seem to want the a#enHon and confidence as much as the drug •  Might work parHcularly well for some ailments such as depression. ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern