Proposition of a dissociative vs. (pain) hypersensitive subtype of patients at risk of suicide

Introduction: The hypothesis of a diminshed pain sensitivity trait as one key contributor to suicidal behavior is recurring across most contemporary theoretical frameworks of suicide. In Joiner's Interpersonal-Psychological Theory, increased pain tolerance, alongside fearlessness about death, is thought to specifically contribute to the acquiring of a capability for suicide. Methods: A critical overview of clinical and neurobiological theoretical, meta-analytical and empirical contributions has been performed, after targeted and in-depth research on electronic databases, leading to the proposition of two different subtypes of patients at risk of suicide. Results: Pain insensitivity as a trait does not seem to effectively distinguish suicide attempters from ideators, and literature does not always suggest such a linear relationship between suicide risk and pain perception. On one hand, building upon Orbach's insights into dissociation, interoception, and pain sensitivity, and incorporating recent meta-analytical and neurobiological research, the presence of a dissociative subtype of individuals at risk of suicide is hypothesized. As possessing higher dissociative traits, some individuals may encounter frequent disruptions in conscious appraisal of pain and disconnections between the processing of interoceptive stimuli and subjective emotional experience, which expose them to a higher risk of suicide attempting. On the other hand, some lines of evidence suggest an opposite pattern of associations between a greater suicide risk and heightened sensitivity to both physical and psychological pain, at least among individuals characterized by chronic inflammation, like depressed patients and people living with chronic pain syndromes. Such findings converge in the hypothesis of a hypersensitive subtype, marked by chronic inflammatory processes, heightened interoceptive vigilance, sensitivity to both physical and psychological pain, and increased suicidal ideation. Discussion: These hypotheses align with neuroimaging studies on post-traumatic stress disorder, which delineate dissociative versus hyperaroused stress-response patterns, and resonate with neuropsychoanalytic perspectives. Moreover, these notions share similarities with recent alternative clustering models of suicidal behavior.