student profile: Mr Christoph Werner


Thesis work

Thesis title: Development and Evaluation of a new Experimental Model of a Perceptible Placebo

Supervisors: Evan LIVESEY , Ben COLAGIURI

Thesis abstract:

This project will investigate the underlying mechanisms of the placebo effect by examining whether the perceptual features of the placebo itself influence the placebo and nocebo effect. Most traditional placebos, e.g. lactose pill, have no perceptual features during or after the process of intake and therefore are not likely to mimic the perceptual features of a real medication administered in clinical practice. This is because most drugs have various perceptible effects on the consumer, e.g. vitamins influencing urine colour or cough pills having an unpleasant taste. This means that using traditional placebos to understand the placebo effect might not accurately reflect the conditions under which placebo effects occur outside the laboratory. So far only Berna et al. (2017) have tried to use a method to account for perceptual features of a medication, but importantly they used another medication for the placebo group to elicit actual physiological side effects. This approach in our opinion creates more problems than it solves. Especially from an ethical point of view, their approach is problematic beacause it uses an active and potent medication as to simulate perceptible drug effects, rather than the perceptible placebo we are proposing. Most importantly, atropine, which they used as the ‘placebo’ can elicit severe side effects like, ventricular fibrillation or tachycardia, which makes it necessary to have close medical attention. Therefore, their model of an active placebo involves a genuine risk to participants’ safety and limits the application to short-term experimental laboratory settings, compared with our benign model of a perceptible placebo. In order to address this, the current project develops a new experimental model to test how the perceptibility of a true placebo influences its effect. The perceptible placebo we will use is a benign food colouring, i.e. beetroot extract, that causes a slight red colouration of urine and has a slightly noticable tast during ingestion, but otherwise has no known biological effects. Across three studies, we will test whether perceptible placebos elicit a higher placebo and nocebo effect than imperceptible placebos, what the psychological mechanisms of any such effect are, and whether perceptible placebos influence beliefs about treatment allocation. The project will shed new light on whether the features of the placebo influence the placebo and nocebo effect.

Note: This profile is for a student at the University of Sydney. Views presented here are not necessarily those of the University.