Altered Interoceptive Processing in Generalized Anxiety Disorder—A Heartbeat-Evoked Potential Research

Abstract

Generalized anxiety disorder (GAD) is one of the most common anxiety disorders. The brain’s dysfunctional processing of interoceptive information is increasingly recognized as an important component of anxiety disorders. However, the neural mechanisms remain insufficiently understood. In the present study, patients with GAD and healthy control participants underwent an eyes-closed (EC) resting state (interoception) and eyes-open (EO) resting state (exteroception) without paying conscious attention to heartbeat. Electrocardiography (ECG) and electroencephalography (EEG) signals were recorded at the same time. The results show that in healthy controls, the heartbeat-evoked brain potential (HEP) was modulated by the conditions, with a significantly higher amplitude under EC than EO, while this was not the case in GAD patients. Further analysis revealed that the dysfunction of HEP modulation in GAD patients may be attributed to excessive interoceptive processing under EO, with a marginally higher HEP in GAD than in the healthy controls. Finally, the right prefrontal HEP amplitude during EC condition was significantly correlated with the severity of the patients’ anxiety symptoms. Our results suggest that altered cortical processing of interoceptive signals may play an important role in the pathophysiology of generalized anxiety disorder.

Altered interoception in patients with borderline personality disorder: a study using heartbeat-evoked potentials

“…Aside from differences in diagnostic features, it is also plausible to assume that divergent task instructions during HEP measurement played a role. In particular, HEP amplitudes seem to be larger under resting EEG conditions with eyes closed, compared to open eyes, which is intuitively understandable, as interoception can be sharpened by precluding input from other sensory systems [32,50,56,60].…”

“…Consistent with these theoretical considerations, altered HEPs have been found in psychopathological disorders that are clinically characterized by reduced capacity for interoception and poor awareness of own feelings. For instance, smaller HEP amplitudes have been observed in depression compared to controls [30], whereas increased amplitudes have been reported in social anxiety disorder [31,32]. To date, only a few studies have investigated interoception in BPD.…”

Altered heartbeat perception sensitivity associated with brain structural alterations in generalised anxiety disorder

“…The volume in the MPFC was seen to be related to heartbeat sensitivity in patients with GAD but not in the healthy population. 25 There are few studies that have examined the relationship between structural MRI and cardiac perception in the healthy population. To our knowledge, it should be the first study to explore the neural structures involved in processing enhanced cardiac perception in patients with GAD.…”

“…Previous research reported that the assessment of heartbeat perception in a solely behavioural or selfreporting questionnaire-based manner is not ideal, and indicated that heartbeat-evoked brain potentials (HEP), an electrocortical potential time locked to the cardiac R wave, might be a more objective quantitative assessment tool. 25 It was proposed to use HEP to evaluate heartbeat perception in future studies. Further limitations are that some patients with GAD received different treatments, which is a well-recognised issue in similar brain structure studies.…”

Feeling the beat: Temporal and spatial perception of heartbeat sensations

“…Another important, and to a degree unexpected, finding within this study of non-clinical individuals was the absence of a relationship between trait anxiety and the timing of heartbeat sensations. Indeed, disrupted interoceptive ability is widely described in people suffering from anxiety disorders (Domschke et al 2010;Garfinkel and Critchley 2013;Khalsa et al 2018;Pang et al 2019;Quadt et al 2018) relationships between interoceptive accuracy and anxiety score are frequently described in 'analogue' populations (e.g. Dunn et al, 2010).…”