Does Interoceptive Sensibility Mediate the Relationship Between Emotional Distress and Pain Severity? A Cross-Sectional Study in Chronic Pain and Pain-Free Individuals.

BACKGROUND: Pain and emotion are strongly related, yet the mechanisms mediating their relationship remain unclear. Interoception, perceiving internal bodily signals, has been implicated in pain-related and emotional processes. Altered interoception was demonstrated in chronic pain (CP) and mental health conditions. This preregistered cross-sectional study examined whether interoceptive sensibility, the self-reported multi-dimensional tendency to monitor bodily sensations, mediated the relationship between pain severity and emotional distress. METHODS: Adults with mixed-aetiology CP (n = 203) and pain free controls (PFC; n = 170) recruited from the community, and treatment-seeking patients with chronic orofacial pain (COFP; n = 89) recruited from a clinic completed measures of pain intensity, pain interference, emotional distress (depression, anxiety, anger) and interoceptive sensibility, specifically the Multidimensional Assessment of Interoceptive Awareness (version 2) and Body Perception Questionnaire. RESULTS: Compared to PFC, both CP groups reported greater pain intensity, pain interference and emotional distress, together with a differential interoceptive profile reflecting greater noticing and perceiving of their bodily sensations, while being more worried and having less trust in these sensations (p-values < 0.001). These interoceptive dimensions did not correlate with pain intensity, yet correlated differentially between groups with emotional distress and pain interference: not-worrying in CP and COFP (remotional = -0.40 and -0.64; rpain = -0.26 and -0.41), noticing in COFP (remotional = 0.43; rpain = 0.39) and trusting in CP (remotional = -0.42; rpain = -0.30). Exploratory partial mediation of the pain interference-emotional distress relationship was demonstrated by these interoceptive dimensions in these groups. CONCLUSIONS: Findings refuted interoceptive sensibility's link with pain intensity while potentially having an underlying role in linking the functional burden of CP with emotional distress. SIGNIFICANCE STATEMENT: Replicating meta-analytic findings regarding dimensions of interoceptive sensibility in chronic pain differing from pain-free controls. Extending to include both community-based and treatment-seeking people with chronic pain, findings refute preregistered hypothesis for associations between measures of interoceptive sensibility and pain intensity, though indicating according to a preregistered exploratory analysis that worrying about bodily sensations statistically mediated the relationship between pain interference and emotional distress. This suggests interoceptive sensibility as an underlying process in the functional and emotional sequelae of chronic pain.