Introduction to the Special Issue on Interoception and Suicidality

Potential association between suicide risk, aggression, impulsivity, and the somatosensory system

Aggression and impulsivity are linked to suicidal behaviors, but their relationship to the suicidal crisis remains unclear. This magnetoencephalography (MEG) study investigated the link between aggression, impulsivity, and resting-state MEG power and connectivity. Four risk groups were enrolled: high-risk (HR; n = 14), who had a recent suicidal crisis; lower-risk (LR; n = 41), who had a history of suicide attempts but no suicide attempt or ideation in the past year; clinical control (CC; n = 38), who had anxiety/mood disorders but no suicidal history; and minimal risk (MR; n = 28), who had no psychiatric/suicidal history. No difference in resting-state MEG power was observed between the groups. Individuals in the HR group with high self-reported aggression and impulsivity scores had reduced MEG power in regions responsible for sensory/emotion regulation vs. those in the HR group with low scores. The HR group also showed downregulated bidirectional glutamatergic feedback between the precuneus (PRE) and insula (INS) compared to the LR, CC, and MR groups. High self-reported impulsivity was linked to reduced PRE to INS feedback, whereas high risk-taking impulsivity was linked to upregulated INS to postcentral gyrus (PCG) and PCG to INS feedback. These preliminary findings suggest that glutamatergic-mediated sensory and emotion-regulation processes may function as potential suicide risk markers.

Body Awareness as a Protective Factor against Suicidal Orientations in College Students

In this study, binary logistic regression and linear regression analyses were used to examine the relationship between interoceptive body awareness and suicidal orientation among Colombian university students. Additionally, the bootstrap technique was employed to resample and estimate the distribution of the data. The results support the idea that greater interoceptive awareness may protect against suicidal orientation by improving emotional regulation. An inverse relationship was found between interoceptive awareness and suicidal ideation. These findings align with previous literature emphasizing the importance of body awareness for emotional well-being. Further longitudinal research is needed to explore this relationship more deeply.

Development and Psychometric Validation of the Body Trust Scale

Interoception (e.g., abilities to recognize/attend to internal sensations) is robustly associated with psychopathology. One form of interoception, body trust, is relevant for the development of disordered eating and suicidal thoughts/behaviors. However, measures of body trust are narrow, despite research suggesting body trust is multifaceted. The aim of this study was to develop a comprehensive measure of body trust: The Body Trust Scale (BTS). 479 U.S. adults completed self-report surveys containing the BTS and psychopathology measures. Exploratory and confirmatory factor analyses revealed a three-factor structure: Comfort with One's Body, Physical Attractiveness, and Comfort with Internal Sensations. Factors showed strong construct, convergent, and divergent validity, as well as moderate predictive validity for suicidal thoughts/non-suicidal self-injury. Furthermore, factors showed strong internal consistency, test-retest reliability, and were invariant across the gender binary. The BTS can be used in research and clinical settings to understand how specific facets of body trust relate to psychopathology.

Longitudinal relationships between specific domains of interoception and muscle dysmorphia symptoms

Muscle dysmorphia (MD) is a subtype of body dysmorphic disorder (BDD); few risk factors for MD symptom development have been identified. One potential risk factor may be decreased interoceptive sensibility (impaired ability to recognize bodily sensations), which is present across a range of mental disorders. Notably, impaired interoceptive awareness is elevated in populations at-risk for MD. Furthermore, interoception is associated with MD symptoms, and theoretically, interoceptive dysfunction may facilitate engagement in MD symptoms. However, longitudinal research on interoception and MD is scarce, and specific MD symptoms implicated in these relationships are unknown. This study examined longitudinal relationships between specific domains of interoceptive sensibility and MD symptoms. Participants were 255 (26.7% Male; 72.1% Female; 1.2% Non-binary) undergraduates who completed two self-report surveys separated by four weeks. A path model was specified in which seven forms of interoception predicted five MD symptoms. Results suggested that interoceptive sensibility characterized by difficulties attending to bodily sensations and viewing these sensations as distracting predicted MD symptoms like muscle checking, positive attitudes towards using muscle-building substances, and compulsive exercise. Specific forms of impaired interoceptive sensibility may represent a risk factor for MD symptoms. If clinicians can increase the interoceptive abilities of their clients at risk for MD, this may prevent the development of MD symptoms.

A Pilot Feasibility Study of Reconnecting to Internal Sensations and Experiences (RISE), a Mindfulness-Informed Intervention to Reduce Interoceptive Dysfunction and Suicidal Ideation, among University Students in India

Although 20% of the world’s suicides occur in India, suicide prevention efforts in India are lagging (Vijayakumar et al., 2021). Identification of risk factors for suicide in India, as well as the development of accessible interventions to treat these risk factors, could help reduce suicide in India. Interoceptive dysfunction—or an inability to recognize internal sensations in the body—has emerged as a robust correlate of suicidality among studies conducted in the United States. Additionally, a mindfulness-informed intervention designed to reduce interoceptive dysfunction, and thereby suicidality, has yielded promising initial effects in pilot testing (Smith et al., 2021). The current studies sought to replicate these findings in an Indian context. Study 1 (n = 276) found that specific aspects of interoceptive dysfunction were related to current, past, and future likelihood of suicidal ideation. Study 2 (n = 40) was a small, uncontrolled pre-post online pilot of the intervention, Reconnecting to Internal Sensations and Experiences (RISE). The intervention was rated as highly acceptable and demonstrated good retention. Additionally, the intervention was associated with improvements in certain aspects of interoceptive dysfunction and reductions in suicidal ideation and eating pathology. These preliminary results suggest further testing of the intervention among Indian samples is warranted.