Lecture 5 Nocebo Effect

MPI illness characteristics

- Ambiguous transient and usually benign symptoms - Most common symp: hyperventilation, headache, cough, abdominal pain, nausea, itching, rash, dizziness, and fainting - High levels of anxiety because people do not know what is going on - Dramatic escalation of causes - Rapid remission of symp - Medical evaluation inconclusive - No toxic agent found - Hostile reaction to MPI hypothesis

infrasound

- Below the threshold of audible sound - Used as explanation for symptom response to wind turbines - Halted construction of a large number of green energy projects - Invisible (obviously, it is a sound) - Ideas of infrasound as causing symptom illness - But constant in environment o In air con, in caused by waves so exposed when on beach, etc

Mass Psychogenic illness - common background characteristics

- Closed cohesive social settings factories, schools, army barracks, convents - Often recent social stress - Dramatic initial episode where someone will collapse from stage like end of year prize giving - Presence of unusual agent

Wind turbine noise in four set of picture of participants

- Concern about windturbine causing sickness based on what people had read on internet - Fionna Criton, Winford Reif (spelling) - Did work in 70's style lounge lab - At main Auckland campus there is a sound testing room by music school o Testing soundproofing of wood and furniture o Can also generate sound o Was able to get them to make infrasound and play it through speakers o Isolated room, and doesn't look like testing medicine and psychology so people more relaxed about doing the experiment

tarantism

- Dancing mania in southern Italy among those who thought they had been bitten by the tarantula - Symp o Difficulty breathing, chest pain, headaches, giddiness, fainting, trembling, thirst, appetite loss - "Cure" o Dancing to up tempo tunes (tarantellas), drinking alcohol - Prognosis o May reoccur in subsequent summers or on hearing tarantellas

MPI spread

- Explosive spread - Initial identifiable index case - Line of sight, oral communication or friendship lines spreads by line of sight, not contact as normal illness does - Often identification with index cause - popular student, part of an in group - Spread often occurs down age scale beginning in older or higher status individuals - High status of "in group" greater response - Greater response in females

perceived sensitivity to medications

- High sensitivity belief and taking meds, more likely to report - Around 20% reported that they were particularly sensitive to medicine

Individual differences in responders to MPI

- Higher levels of anxiety - Higher rates among females - Higher family disruption divorce, family drama, etc - Higher rates of previous absenteeism and medical consolation

does the restriction of choice influence the nocebo response?

- If you don't give choice, does it affect nocebo/placebo response? - Conducted in a lab, not real life setting - 61 participants - Total purpose of study was to test whether choice would influence effectiveness of beta-blocker medication in reducing examination anxiety cover story - Excluded if currently taking any medication that could interact with beta-blocker or had medical condition in which beta-blockers contraindicated - Told active ingredient 50mg metoprolol (actually placebos) - Side effects: headache, nausea, drowsiness, dizziness, sore throat, dry mouth, itching, stomach pain, cold hands and feet

nocebo measurement issue: influence of negative affect

- Influence of nocebo effect on perceived drug effectiveness o Not as studied Linear relationship? More symp bad, few symp good? o If side effects people feel drug not effective o Framing important If told that there is side effects and they are sign its working (cancer treatment study) - Assessing prior symptoms - Self-report versus outcome measure - medical visits, functional outcomes (days off) - Assessing the attribution process - Y/N/Maybe? o Not straight forward as Yes and No. Often its "maybe it is, maybe it isn't?" - Short and delayed effects - use of ecological momentary assessment?

expectations and nocebo effect from medication

- Many people have a large number of symptoms available for misattribution - Presentation of medication side effect information is poor and promotes the nocebo effect - Data suggests man symptoms misattributed to the effects of medication - Large percentage of population believe they are very sensitive to the effects of medication - More likely to use medical care, report side effects, and unusual symptoms

How are nocebo effects generated?

- Misattribution o At heart of nocebo response o Belief that the symp you have, because of expectations, are attributed to the medication or stimulus - Increased anxiety o Cause symp in themselves and there can be a nocebo effect caused through classical conditioning - Expectations - Classical conditioning o See this with people undergoing chemotherapy Paired with feeling nauseous and vomiting - over time the stim itself can come to cause the nauseous and vomiting (sign of the nurse or oncologist)

the role of choice

- No choice decreased placebo and increased nocebo response - Effect of choice likely to be more striking with real world choices - Why does choice affect drug response? - Moves to contain costs - switching to single funded medication may reduce drug efficacy and increase side effects through psychological mechanisms - Maybe effect would be stronger if in real world situation not a study on exam anxiety - People take credit for good things that happen when we make a choice and if we don't have a choice we blame the negative things that happen on the thing that we had no choice over.

Explanation and nocebo effect from environmental stimulus

- Nocebo effect from environmental source more common than recognised - Studies show same environmental stimulus can be easily famed as positive or negative to produce corresponding effects - Nocebo explanation is seen as plausible - Nocebo explanation reduces symptoms and concern

nocebo measurement issue: attribution

- People have previous symp, give people a drug, then have symp measured after - some are previous symp that they are now attributing to medication even if they had it before - Can have new symp that they don't attribute - New symp they do attribute

social modelling and side effects

- Told them side effects and intended effects o Unbeknownst to people in study, had a confederate (someone working for them) out in waiting room. o Give subject betaprol and have them wiat 10 min in the waiting room, let them know others might be in study out there o Person sat next to confederate and there is social modelling - Bigger effect for females in the group - Females watching female model reported more side effects and attributed more symp to medication - Females still reported more symp when male model. - Level of empathy impact level of symp reported

Nocebo defn

The experience of adverse events or unpleasant symptoms in response to an inert medication, procedure or stimulus

Nocebo effects

• Arthur Barskey- at Harvard - did review of nocebo effects as below - Incidence of adverse effects - 25% in review of 109 double blind trials o When specifically asking for particular symptoms the rate goes up - Higher when side effects specifically asked for (27-71%) - In trials for diseases that are asymptomatic - incidence can exceed active medication - Dependence o On placebo and inert medication - Nocebo effects more common in women - Largely unrecognised o In terms of burden and side effects in medicine

1) How you would investigate whether the twitching was an MPI? Make a list of the factors you would consider in your investigation?

• Time line • Patient zero • How has it spread o Line of sight? • Gender differences • Recover time due to env change

2) Make a list of the specific advice in order of importance you would give to manage the problem?

• What to tell people • That its common • Reassure them that nothing has been found • That these symp improve quickly - give time line • Ensure there is no physical cause and that it is more than likely in relation to stress