Relationship between symptom perception distortion as assessed in different experimental paradigms in patients with functional disorders.

Abstract

Aims: Patients with functional somatic syndromes (FSS) show a reduced correspondence between induced physiological changes and self- reported symptoms in a rebreathing paradigm. Patients with FSS also report elevated symptoms unrelated to physiological changes after induction of negative affective states in an affective picture viewing paradigm (Van Den Houte et al., 2017, Psychosom Med, 79, 1000 -7; Van Den Houte et al., 2018, J Psychosom Res, 106, 49-55). Here, we investigated whether distorted symptom perception in one paradigm was associated with distorted symptom perception in the other paradigm, and we explored the role of individual difference variables in these effects. Methods: Patients (N=81, 71 women; mean age = 42.67, SD = 10.62) with fibromyalgia and/or chronic fatigue syndrome participated in a test session comprising 4 well-validated paradigms, among which the picture viewing and the rebreathing paradigm. Using multiple mixed model analyses, it was tested whether elevated symptoms resulting from inducing a negative affective state had an effect on dyspnea ratings during recovery from CO2-inhalation. In an exploratory way, we assessed the role of several individual difference variables as moderators. Results: There was no relationship between a patient’s symptom induction effect in the picture paradigm and the patient’s level of distortion in dyspnea perception during recovery. Negative affect was a moderator in both paradigms. Absorption and the difficulty identifying feelings moderated the symptom induction effect after picture viewing, whereas the amount of symptoms in daily life (PHQ) moderated perceived dyspnea. Conclusions: Whereas both paradigms investigating symptom perception processes have demonstrated distortions in FSS patient, distorted symptom perception in one paradigm is unrelated to distortion in the other paradigm. Only trait NA moderated effects in both paradigms.