Interoceptive Abnormalities and Suicidality: A Systematic Review

Dysfunction of interoception (i.e., difficulties sensing the physiological state of one's own body) is increasingly linked to different mental health disorders and suicidal outcomes. The aim of this study was to systematically review the literature on the association between suicidality and interoception, as well as identify potential confounders and mediators of the relationship. We conducted a systematic review of four databases, allowing for critical examination of the role of different measures of interoception (accuracy, sensibility, awareness, cognitive/emotional evaluation) across the suicide continuum (ideation, plans, attempts, deaths). The search strategy identified 22 studies (14,988 participants). Preliminary but limited evidence was found for impaired interoceptive accuracy among those reporting suicide attempt histories. We found evidence of interoceptive sensibility disturbances across the suicide continuum, including experiences of not trusting one's own body sensations and impaired abilities to sustain and control attention to such sensations. Consistent evidence was also reported for disturbances related to cognitive and emotional evaluations of interoceptive sensations. The latter was particularly pronounced for those reporting suicide attempts, relative to those reporting suicidal thinking or planning alone. Overall, this review's results suggest that interoceptive abnormalities are potentially important indicators of risk for suicidal thinking, intentions, and behaviors. However, due to the inconsistent adjustment for variables of interest, and cross-sectional designs, it is unclear whether interoceptive changes and disturbances have a direct role, or whether the association is explained and mediated by key third variables (e.g. depression, disordered eating, emotional dysregulation). We discuss the implications with respect to suicidal risk and therapeutic interventions.