Effect of Genetic Information and Information About Caffeine Content on Caffeine Withdrawal Symptoms

Llewellyn Mills,Ben Colagiuri,Ilan Dar-Nimrod

doi:10.1038/s41598-017-08678-4

Llewellyn Mills, Ben Colagiuri + Show 1 more

Open Access

https://doi.org/10.1038/s41598-017-08678-4

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Journal: Scientific Reports	Publication Date: Aug 21, 2017
Citations: 6	License type: open-access

Affiliation: University of Sydney

Abstract

This study sought to test the effect of genetic information and information about the caffeine content of a beverage on caffeine withdrawal, specifically if: (1) being informed that one has tested positive for a gene related to caffeine withdrawal can produce an exaggerated caffeine withdrawal response during abstinence; (2) belief that one has consumed caffeine leads to a reduction in withdrawal symptoms when no caffeine is consumed. Regular coffee drinkers were given a bogus genetic test and were told either that they had tested positive or negative for a gene related to withdrawal. After 24-hour caffeine abstinence withdrawal symptoms were measured using a self-report caffeine withdrawal scale, and then again after a cup of decaffeinated coffee. Half the participants were told their coffee was caffeinated and half were told truthfully that it was decaffeinated. Participants told the coffee was caffeinated reported a greater reduction in withdrawal symptoms than those told it was decaffeinated. Differing genetic test result information produced no difference in reported withdrawal symptoms. These results indicate that information about the dose of caffeine administered can influence withdrawal symptoms, but that genetic information does not have a universal ability to produce nocebo effects across all sensory and cognitive domains.

Highlights

Finding out we have a gene associated with a medical condition can exert a powerful influence on our thoughts, emotions, and behaviour
One study by Dar-Nimrod and Colleagues found that healthy participants who were informed they possessed a gene associated with alcoholism following a bogus genetic test reported a significantly greater increase in negative affect and significantly lower reduction in positive affect than those told they did not possess the gene[8]
A general increase in negative affect brought about by information alone is consistent with the definition of a nocebo effect but negative affect confined solely to worry about future risk of alcoholism is not

Summary

Introduction

Finding out we have a gene associated with a medical condition can exert a powerful influence on our thoughts, emotions, and behaviour. One study by Dar-Nimrod and Colleagues found that healthy participants who were informed they possessed a gene associated with alcoholism following a bogus genetic test reported a significantly greater increase in negative affect and significantly lower reduction in positive affect than those told they did not possess the gene[8]. Whether this result could be termed a nocebo effect depends on the nature of the negative affect. For example being exposed to warnings about side-effects of a medication on a consent form can increase reporting of cognitive deficits in chemotherapy patients[17], gastrointestinal complaints in treatment of unstable angina with aspirin[20], and insomnia in participants reporting sleep difficulty[21]

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