Changes in Interoceptive Accuracy Related to Emotional Interference in Somatic Symptom Disorder

Abstract

Abstract Objective: Patients with somatic symptom disorder (SSD) tend to have problems perceiving their bodily signals. We hypothesized that SSD patients would exhibit changes in interoceptive accuracy (IA), particularly when emotional processing is involved. Methods: Twenty-three patients with SSD and 20 healthy controls were recruited. IA was assessed using the heartbeat perception task. The task was performed in the absence of stimuli as well as in the presence of emotional interference, i.e., photographs of faces with an emotional expression. IA were examined for correlation with measures related to their somatic symptoms, including resting-state heart rate variability (HRV). Results: There was no significant difference in the absolute values of IA between patients with SSD and healthy controls, regardless of the condition. However, the degree of difference in IA without emotional interference and with neutral facial interference was greater in patients with SSD than in healthy controls (p=0.039). The IA of patients with SSD also showed a significant correlation with low-frequency HRV (p=0.004) and high-frequency HRV (p=0.007). Conclusion: SSD patients showed more significant changes in IA when neutral facial interference was given. These results suggest that bodily awareness is more affected by emotionally ambiguous stimuli in SSD patients than in healthy controls.