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

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.

Interpersonal Problems, Mindfulness, and Therapy Outcome in an Acceptance-Based Behavior Therapy for Generalized Anxiety Disorder.

OBJECTIVE: To better understand the role interpersonal problems play in response to two treatments for generalized anxiety disorder (GAD); an acceptance-based behavior therapy (ABBT) and applied relaxation (AR), and to examine how the development of mindfulness may be related to change in interpersonal problems over treatment and at follow-up. METHOD: Eighty-one individuals diagnosed with GAD (65.4% female, 80.2% identified as white, average age 32.92) were randomized to receive 16 sessions of either ABBT or AR. GAD severity, interpersonal problems, and mindfulness were measured at pre-treatment, post-treatment, 6-month follow-up, and 12-month follow-up. RESULTS: Mixed effect regression models did not reveal any significant effects of pre-treatment interpersonal problems on GAD severity over treatment. After controlling for post-treatment GAD severity, remaining post-treatment interpersonal problems predicted 6- but not 12-month GAD severity. Participants in both conditions experienced a large decrease in interpersonal problems over treatment. Increases in mindfulness over treatment and through follow-up were associated with decreases in interpersonal problems, even when accounting for reductions in overall GAD severity. CONCLUSIONS: Interpersonal problems may be an important target of treatment in GAD, even if pre-treatment interpersonal problems are not predictive of outcome. Developing mindfulness in individuals with GAD may help ameliorate interpersonal difficulties among this population.