Understanding the psychology of the nocebo effect

The nocebo effect is increasingly recognized as a powerful determinant of negative health outcomes across a range of symptoms, diseases, and treatments. Like the placebo, nocebo effects are generated by factors surrounding the treatment context, rather than active ingredients of treatments themselves. This chapter first describes the wide range of conditions in which nocebo effects have been clinically and experimentally demonstrated, including, pain, side-effects, and gastrointestinal symptoms. We then discuss the nocebo effect as a learning phenomenon, highlighting the ways by which verbal, conditioned, and social cues are integrated to produce nocebo effects. The chapter then explores mechanisms from psychology and neurobiology implicated in translating this learning to nocebo effects, including expectancy, anxiety, attention, and dispositional factors. Finally, the chapter identifies three potential mitigation strategies, which show some promise in minimizing the clinical burden of the nocebo effect.