High symptom reporters are less interoceptively accurate in a symptom-related context

Objective: We investigated the role of a symptom interpretation frame on the accuracy of interoception and on retrospective symptom reporting in nonclinical high and low reporters of medically unexplained symptoms. Methods: All participants (N=74) went through two subsequent trials of the Rebreathing Test, inducing altered respiration and other physical sensations as a result of a gradually increasing pCO₂ level in the blood. Each trial consisted of a baseline (60 s), a rebreathing phase (150 s), and a recovery phase (150 s). In one trial, the sensations were framed in a neutral way ("the gas mixture might alter breathing behavior and induce respiratory sensations"). In the other trial, a symptom frame was induced ("the gas mixture might alter breathing behavior and induce respiratory symptoms"). Breathing behavior was continuously monitored, subjective sensations were rated every 10 s, and after each trial, participants filled out a symptom checklist. Within-subject correlations between the subjective rating and its physiological referent were calculated for the rebreathing phase and recovery phase of each trial separately. Results: High symptom reporters had more (retrospective) complaints than low symptom reporters, especially in the symptom trial. Only in the symptom frame were high symptom reporters less accurate than low symptom reporters. The reduction in interoceptive accuracy (IA) in high symptom reporters was most striking in the recovery phase of the symptom frame trial. Conclusion: A contextual cue, such as a reference to symptoms, reduced IA in high symptom reporters and this was more so during recovery from the symptom induction.