Does symptom perception after negative affect induction differ between physically ill and healthy individuals? An experimental study within SOMA.CK.

INTRODUCTION

Symptom perception is highly subjective and shaped by complex biopsychosocial factors. This study examined whether negative affect induction using the Affect and Symptoms Paradigm (ASP) influences symptom perception in patients with non-dialysis chronic kidney disease (ND-CKD) and healthy controls.

METHODS

Participants watched three picture series (positive, negative, neutral) from the International Affective Picture System (IAPS). After each series, participants rated symptom levels (10-item-symptom-checklist), affective state (Positive and Negative Affect Schedule) and arousal (Self-Assessment-Manikin-System). Associations of the ASP effect with symptom burden at 6 and 12 months was analysed in the CKD group.

RESULTS

In N = 115 individuals with ND-CKD from the SOMA.CK study (mean age = 62.95, SD = 12.60) and 100 age- and sex-matched healthy controls (mean age = 60.00, SD = 12.80) negative pictures significantly increased negative affectivity and arousal. Symptom levels were higher after viewing negative versus positive/neutral pictures in both groups, but no significant interaction emerged, indicating a comparable response in both groups. Habitual symptoms did not moderate symptom levels after affect induction, although high habitual symptom reporters showed higher symptom levels across all picture categories. In the CKD group difficulties in identifying feelings moderated symptom levels after affect induction. The ASP effect predicted CKD-specific symptom burden at 6 months.

CONCLUSION

Negative affect induction increases symptom levels in a chronic illness such as CKD. These results align with the predictive processing model which suggests that symptom perception develops from a complex inferential process of somatosensory input in light of pre-existing symptom representations in memory.