Understanding persistent physical symptoms: Conceptual integration of psychological expectation models and predictive processing accounts

Persistent physical symptoms (PPS) are distressing, difficult to treat, and pose a major challenge to health care providers and systems. In this article, we review two disparate bodies of literature on PPS to provide a novel integrative model of this elusive condition. First, we draw on the clinical-psychological literature on the role of expectations to suggest that people with PPS develop dysfunctional expectations about health and disease that become increasingly immune to disconfirmatory information (such as medical reassurance) through cognitive reappraisal. Second, we invoke neuroscientific predictive processing accounts and propose that the psychological process of 'cognitive immunization' against disconfirmatory evidence corresponds, at the neurobiological and computational level, to too much confidence (i.e. precision) afforded to prior predictions. This can lead to an attenuation of disconfirming sensory information so that strong priors override benign bodily signals and make people believe that something serious is wrong with the body. Combining these distinct accounts provides a unifying framework for persistent physical symptoms and shifts the focus away from their causes to the sustaining mechanisms that prevent symptoms from subsiding spontaneously. Based on this integrative model, we derive new avenues for future research and discuss implications for treating people with PPS in clinical practice.