Nocebo response: individual differences, network structure, and heterogeneity
Creators: name: Cottam, Martha
name: Terhune, Devin
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Clinical Psychology
subject: Health Psychology
subject: Cognitive Psychology
subject: Social and Behavioral Sciences
subject: Psychology
subject: FOS: Psychology

description: Nocebo effects have been well documented throughout the health and medical literature and are defined as the worsening of symptoms due to prior beliefs, negative-health information or suggestion (Colloca et al., 2020, New England Journal of Medicine). Popular public reports of perceived adverse symptoms arising from environmental factors include responses to vaccines, genetically modified food (GMO) and electromagnetic fields from mobile phones or wireless technologies (Verrender et al., 2018, Environmental Research). Preliminary evidence suggests there is no direct causal link between the environmental trigger and the manifestation of such adverse symptomatology, but rather a nocebo response, which interacts with broader psychosocial factors (Blasini et al., 2017, Pain Reports). Nocebo responses have been demonstrated to surpass the individual, targeting wider communities, in a phenomenon known as mass psychogenic illness (Popkirov et al., 2019, Lancet Neurology). One further environmental source for negative symptom misattribution is the sub-audible occurrence of infrasound from wind turbines. Empirical evidence has previously found no causal link between negative symptoms attributed to wind turbine-generated infrasound exposure, and thus these symptoms are hypothesized to result from negative prior expectations and media reports (Crichton et al., 2015, Environmental research). Determining the underlying cognitive mechanisms that contribute to the nocebo response has a central role in both the management of patient experiences and outcomes, along with strengthening current understanding of psychosomatic symptoms (Rief &amp; Petrie, 2016, Frontiers in Psychology). Relatedly, characterizing the predictors, network structure, and heterogeneity of nocebo responses will help to advance knowledge of the extent to which certain individuals are more prone to these effects. One cognitive framework within which the nocebo response can potentially be fruitfully modelled is predictive processing (Büchel et al., 2014, Neuron; Ongaro et al., 2019, Pain). Nocebo’s positive counterpart, placebo analgesia, has received increased attention with a large body of both theoretical and empirical work proposing that somatic symptoms arise from Bayesian predictive processes (e.g., Büchel et al., 2014, Neuron). Although a similar level of attention has not been directed towards nocebo responses, preliminary work has begun to elucidate a similar role of Bayesian priors and the role of suggestion in the manifestation of somatic symptoms (Bräscher et al., 2020, Psychosomatic Medicine). According to this framework, somatic and other symptoms arise from inference generation from both priors and expectations about specific stimuli. However, a gap in current understanding remains, where this effect has failed to be tested in nocebo paradigms arising from ‘real world stimuli’ and environmental sources such as symptom reporting following infrasound generated from wind turbines. Comparably, it remains unclear whether nocebo responding can be predicted from individual differences factors related to predictive processing, such as suggestibility, which has been conceptualized within the framework of predictive processing (e.g., Martin &amp; Pacherie, 2019, Psychological Review) and shown to predict nocebo hyperalgesia (Corsi &amp; Colloca, 2017, Frontiers in Psychology), placebo hypoalgesia (Parsons et al., 2021, Psychosomatic Medicine) and symptoms associated with environmental factors (also known as idiopathic environmental intolerance; Stein et al., submitted). The present study seeks to determine whether a nocebo manipulation involving ambiguous sound can produce minor symptoms and impair selective attention. We further sought to investigate whether the magnitude of the nocebo response scales with previous symptom profiles, suggestibility, dissociation, and their interaction; to characterize the network structure of the nocebo response; and to evaluate whether heterogeneity in the nocebo response arises from the presence of discrete latent subtypes of nocebo responders.