Mechanistic studies in pathological health anxiety: A systematic review and emerging conceptual framework

Abstract

Background: Pathological health anxiety (PHA) (e.g., hypochondriasis and illness anxiety disorder) is common in medical settings and associated with increased healthcare costs. However, the psychological and neurobiological mechanisms contributing to the development and maintenance of PHA are incompletely understood.

Methods: We performed a systematic review to characterize the mechanistic understanding of PHA. PubMed, PsycINFO, and Embase databases were searched to find articles published between 1/1/1990 and 12/31/2022 employing a behavioral task and/or physiological measures in individuals with hypochondriasis, illness anxiety disorder, and PHA more broadly.

Results: Out of 9141 records identified, fifty-seven met inclusion criteria. Article quality varied substantially across studies, and was overall inadequate. Cognitive, behavioral, and affective findings implicated in PHA included health-related attentional and memory recall biases, a narrow health concept, threat confirming thought patterns, use of safety-seeking behaviors, and biased explicit and implicit affective processing of health-related information among other observations. There is initial evidence supporting a potential overestimation of interoceptive stimuli in those with PHA. Neuroendocrine, electrophysiology, and brain imaging research in PHA are particularly in their early stages.

Limitations: Included articles evaluated PHA categorically, suggesting that sub-threshold and dimensional health anxiety considerations are not contextualized.

Conclusions: Within an integrated cognitive-behavioral-affective and predictive processing formulation, we theorize that sub-optimal illness and health concepts, altered interoceptive modeling, biased illness-based predictions and attention, and aberrant prediction error learning are mechanisms relevant to PHA requiring more research. Comprehensively investigating the pathophysiology of PHA offers the potential to identify adjunctive diagnostic biomarkers and catalyze new biologically-informed treatments.

Keywords: Cyberchondria; Health anxiety; Hypochondriasis; Illness anxiety disorder; Pathological health anxiety.

Figure 1.. PRISMA flow diagram depicting article selection for this systematic review.

Figure 2.. Cognitive, behavioral, and affective mechanisms in the literature that contribute to the development and/or maintenance of pathological health anxiety.

Figure 3.. Schematic representation of an emerging (work-in-progress) predictive processing framework to conceptualize pathological health anxiety.

1) People with PHA may have narrow illness/health concepts that are informed by prior life experiences (e.g., personal or family experiences with other medical conditions). 2) The brain issues predictions about upcoming experiences based on available concepts, and in the case of pathological health anxiety we speculate that there is a bias towards issuing illness- or poor health-related predictions. 3) When the incoming sensory information does not match the prediction (e.g., a good health affirming test result in the context of a comprehensive evaluation for a given medical complaint), a prediction error occurs. In such an instance, there may also be a failure to adaptively perform prediction error learning. 4) While considerably more research is needed to determine the presence and nature of potential interoceptive disturbances in individuals experiencing pathological health anxiety, aberrant interoceptive processing may contribute to the failure to adaptively learn from prediction errors. The picture is freely available in the public domain at https://www.pexels.com and was edited.