Andrew Geers
Professor of Psychology, University of Toledo, United States of America.

An analysis of cognitive and affective factors involved in nocebo effects

Nocebo effects refers to unpleasant treatment responses or worsening of treatment outcomes that arise from medical procedures/contexts, but are not caused by the treatment itself. Research finds that nocebo effects can be caused by expecting adverse treatment responses. Laboratory and clinical research has demonstrated that nocebo expectations can originate from the verbal delivery of information, such as physician warnings, as well as by non-verbal indicators of adverse treatment effects, such as social observations. This situation poses a challenge for clinical care: There is an ethical obligation to notify individuals about possible adverse effects of treatment, however, supplying this information risks inducing these harmful responses due to the generation of nocebo expectations.

Currently, little is known regarding the variables that reduce the likelihood that negative expectations cause nocebo effects in clinical care. Uncovering such information would aid our understanding of nocebo effects and provide practical tools for reducing these adverse outcomes. In this presentation, a distinction is made between cognitive and affective processes in nocebo effects. Following this distinction, it is suggested that there are both cognitive and affective approaches for reducing nocebo effects. To date, approaches for curtailing nocebo effects have used a cognitive approach, such as changing how adverse symptom information is communicated to patients. In this presentation, the merits of using affective and emotional approaches to mitigating nocebo effects will be discussed. Additionally, several experiments will be presented that tested the hypothesis that nocebo effects can be lessened through affective modulation.



Andrew L. Geers, Ph.D. is a Professor of Psychology at the University of Toledo (USA) and completed his degree at Ohio University. His research focuses on the advancement and application of social psychology theory within health and medical contexts. This research typically concerns (1) how beliefs/expectations shape the outcome of medical treatments and interventions (placebo/nocebo effects), (2) the causes and consequences of optimistic or pessimistic evaluations of future events, (3) the effects of involving individuals in their own health care decision making and (4) how to increase the initiation and maintenance of healthy behavior. He has published numerous empirical and conceptual review articles and his research has been funded by the National Institutes of Health.