Placebo and nocebo effects in itch : from conditioning to psychophysiological effects

This dissertation investigated placebo and nocebo effects in itch. Placebo and nocebo effects are positive and negative treatment outcomes respectively, that cannot be attributed to active treatment ingredients. Consistent with previous research, the dissertation shows that these effects play an important role in itch. The studies moreover illustrate that placebo effects can still occur when people are informed about them.The results described in this dissertation show that expectations about itch can be formed in various ways. People's expectations of treatment outcomes have been found underlie placebo and nocebo effects. For instance, the information that is given about how much itch an experimental test elicits (i.e., verbal suggestions) can influence expectations and lead to placebo or nocebo effects. The results also show that placebo effects can be automatically induced for itch by associative learning (through pharmacological conditioning). In addition, these effects may also occur when people know they are placebo effects. These results illustrate the importance of expectations and the psychosocial context in the treatment of somatic symptoms complaints such as itch. The results of this thesis may help improve existing treatments for itch. For example, medicine use can potentially be reduced by applying pharmacological conditioning, existing treatment can be improved by providing optimal treatment information, and the importance of expectations for treatment outcomes can be discussed with patients.The research was funded by a Consolidator Grant from the European Research Council (ERC), granted to A.W.M. Evers.Health and self-regulatio

Can contagious itch be affected by positive and negative suggestions?

Contagious itch can be evoked by observing people scratching. Verbal suggestions about to-be-received itch can influence itch intensity, as shown by placebo research, but it is unknown whether this extends to contagious itch. The current study aimed to replicate prior findings that listening to scratching and rubbing sounds elicits contagious itch, and to investigate whether suggestions can modulate this process. Healthy participants (n = 140) received positive or negative suggestions about itch in response to the sounds (aimed to decrease or increase expected itch, respectively), or no specific suggestions as a control. Participants listened to a number of audio fragments with scratching and rubbing sounds. The amount of expected itch as well as itch sensation after each audio fragment were measured by self-report. Suggestions had no effect on the expected itch. Both rubbing and scratching sounds significantly elicited itch in all groups. Scratching sounds induced more itch than rubbing sounds exclusively in the control group. These findings indicate that short suggestions might be not effective enough to modify the expectations of people regarding contagious itch. Furthermore, suggestions modulate contagious itch to some degree, but not in the hypothesized direction. Potential similarities and differences in the neurobiological mechanisms of contagious itch and nocebo effects are discussed.Stress-related psychiatric disorders across the life spa

Can contagious itch be affected by positive and negative suggestions?

Health and self-regulatio

Conditioning immune and endocrine parameters in humans: A systematic review

FSW - Self-regulation models for health behavior and psychopathology - ou

Antipruritic placebo effects by conditioning H1-antihistamine

Health and self-regulatio

''Consensus on placebo and nocebo effects connects science with practice:'' reply to ''questioning the consensus on placebo and nocebo effects”

Health and self-regulatio

What should clinicians tell patients about placebo and nocebo effects? Practical considerations based on expert consensus

Science Communication and Societ

Effects of Open- and Closed-Label Nocebo and Placebo Suggestions on Itch and Itch Expectations.

Dataset for 'Effects of Open- and Closed-Label Nocebo and Placebo Suggestions on Itch and Itch Expectations'

Effects of Open- and Closed-Label Nocebo and Placebo Suggestions on Itch and Itch Expectations.

Dataset for 'Effects of Open- and Closed-Label Nocebo and Placebo Suggestions on Itch and Itch Expectations'

Open- and closed-label placebo and nocebo suggestions about a sham transdermal patch

Health and self-regulatio