Introduction:The effects of specific suggestions are usually studied by measuring parameters that are directly addressed by these suggestions. We recently proposed the use of a uniform, unrelated, and objective measure like maximal muscle strength that allows comparison of suggestions to avoid nocebo effects and thus to improve communication. Since reduced breathing strength might impair respiration and increase the risk of post-operative pulmonary complications, the aim of the present study was to evaluate the effects of the suggestions on respiratory muscle power. (...) Both the identification and neutralization of negative suggestions in the clinical context and stimulating suggestions could improve breathing force, a predictor of physical fitness and convalescence.MethodsIn 50 healthy, adult volunteers, respiratory muscle strength was measured by maximal inspiratory and expiratory pressures, as well as by maximal inspiratory and expiratory flows. Baseline was compared to values after application of eleven suggestions, five out of clinical context, including memory of negative or positive past, risk information for informed consent, and a non-verbal suggestion. Six stimulating suggestions included self-affirmation, empowering words, a heroic mirror image, and an imagination.ResultsAll suggestions showed an impact on respiratory muscle strength, indicating placebo and nocebo effects. No single parameter could represent the breathing force in its complexity, however, trends and different specific aspects of it were measured. The strongest reaction was observed with the recall of a previous negative situation resulting in a reduction in expiratory flow to 96.1% of baseline. After risk information, a decrease was observed in three of the parameters, with the highest extend in expiratory pressure by 4.4%. This nocebo effect was neutralized by adding positive aspects to the risk information. Every intended strengthening suggestion resulted in statistically significant increases of at least one parameter, with changes of up to 10%, indicating placebo effects. Here, expiration was more affected than inspiration. Sex was the only influencing factor reaching statistical significance, with stronger reactions in women.ConclusionRespiratory muscle strength proved to be sensitive to suggestions with clinical context, as well as suggestions intended for stimulation. With this objective measurement, evaluation, and comparison of different suggestions is possible to help avoid nocebo effects. The demonstrated effect of supporting suggestions can be followed up and used in clinical practice. (shrink)

Drug recalls and lawsuits against pharmaceutical manufacturers are accompanied by announcements emphasizing harmful drug side-effects. Those with elevated health anxiety may be more reactive to such announcements. We evaluated whether health anxiety and financial incentives affect subjective symptom endorsement, and objective outcomes of cognitive and physiological functioning during a mock drug recall. Hundred and sixty-one participants reported use of over-the-counter pain medications and presented with a fictitious medication recall via a mock Food and Drug Administration website. The opportunity to join (...) a class-action lawsuit was manipulated. We assessed health anxiety, recalled drug usage, blood pressure, heart rate, and performance on a computerized Trail Making Test. Symptom endorsement was strongly predicted by health anxiety. When combined, three health anxiety measures explained 28.5% variance. These effects remain strong after controlling for depression and anxiety. Litigation condition did not predict symptom endorsement. Blood pressure and heart rate were modestly predicted by health anxiety, but not by litigation condition. TMT performance was consistently predicted by health anxiety, with higher scores associated with poorer performance. Although there were no main effects for litigation, interactions consistently emerged for the TMT, with generally poorer performance for those with higher health anxiety in the non-litigation condition; whereas health anxiety was unrelated to performance for the litigation condition. All but one participant joined the litigation when given the opportunity, despite a healthy sample and minimal use of pain medication. Subsequent data from 67 individuals with no mention of the FDA scenario or litigation showed that health anxiety still significantly predicts symptom endorsement, but the explained variance is less than half that obtained in the FDA scenario. The findings suggest that health anxiety plays a significant role in adverse symptom reporting, beyond anxiety or depression, and this effect is independent of the presence of the FDA recall. The lack of differences for health anxiety and symptom endorsement between litigation and non-litigation conditions rules out malingering. Although it is general practice in drug recalls to list potential adverse side effects caused by medications, this may elicit unintended symptom experiences and health anxious individuals may be more susceptible. (shrink)