Fearlessness About Death is Related to Diminished Late Positive Potential Responses When Viewing Threatening and Mutilation Images in Suicidal Ideators

Background: Very few people who desire death by suicide ever make a suicide attempt, highlighting the importance of determining factors that influence the capability to enact lethal self-harm. One such factor is fearlessness about death, which has been found to be an important predictor of suicide attempts. Recently, longitudinal evidence found that fearlessness about death is positively associated with fluctuations in suicidal ideation. Efforts exploring biophysical mechanisms of suicide have found diminished physiological responses to threat/mutilation-related images in suicide attempters and in individuals who report being less fearful of death. These studies suggest that an individual with greater fearlessness about death may demonstrate a blunted response to threat/mutilation stimuli; however, this hypothesis has yet to be directly tested. Methods: This study used an electroencephalography/event-related potential paradigm to examine late positive potential (LPP) amplitude differences in an adult community sample (N = 280), as well as a subsample with current suicidal ideation (n = 62), with a high rate of psychopathology (90.1%). It was hypothesized that participants with higher fearlessness about death would show diminished responses (smaller LPP amplitude) when viewing threat/mutilation images. Results: Results indicated that participants with suicidal ideation and elevated fearlessness about death demonstrated a blunted emotional response to threat/mutilation images but similar reactions to rewarding pleasant stimuli. Conclusions: These results suggest blunted LPP responses to threat/mutilation stimuli may be a potential biophysical mechanism for fearless about death