Moving beyond the Pain-Suicidality Link: An Investigation of Fluctuations in Social Threat and Neural Response to Social Threat in Momentary Pain and Proximal Risk for Suicidal Ideation in Adolescence - PROJECT SUMMARY/ABSTRACT Suicide rates are the second leading cause of death in adolescence. Suicidal ideation (SI) typically develops in adolescence. The onset of SI is a developmental inflection point associated with pathways toward persistent and worsening SI and other self-injurious thoughts and behaviors. SI is also associated with significant health care costs, morbidity, and risk for mortality. Rates of physical pain increase in adolescence alongside the developmental increase in suicide risk. The presence of physical pain is associated with a 2- to 3-fold increase in SI risk, prompting several major organizations (e.g., World Health Organization, American Psychiatric Association, and American Foundation for Suicide Prevention) to highlight physical pain conditions as a serious risk factor for suicide in adults and children ages 10 years and older. Multiple suicide theories posit that suicidal thoughts and behaviors arise from the desire to escape unbearable pain, including physical pain. However, research on the pain–suicidality link has heavily relied on cross-sectional studies focusing on pain diagnoses (e.g., chronic pain) as a single risk factor. Yet, most individuals with a pain diagnosis do not have SI. There is a need for longitudinal studies investigating how multiple risk factors work together to influence SI. There is also a need to identify proximal risk for SI (e.g., over hours) given that SI often fluctuates rapidly over short periods. We will move beyond the pain–suicidality link by investigating factors that may influence dynamic changes in physical pain and proximal risk for SI among adolescents. We will investigate the effects of short-term effect of social threat (threat to social status or relationships) and individual differences in neural response to social threat on momentary increases in physical pain and proximal risk for SI. We focus on social threat because this is an especially developmentally salient type of threat in adolescence and has been shown to influence pain. Social threat, like physical threat, also activates pain-related brain regions involved in a “neural alarm system” to warn against danger. Social threat is also a robust longitudinal predictor of SI in adolescence. To address major gaps in knowledge of the role of social threat in the pain–suicidality link, we will test components of an overarching model positing that exposure to social threat predicts momentary increases in pain (particularly pain unpleasantness). Pain in turn is a proximal predictor of SI. Heightened neural activation in pain-related brain regions to social threat amplifies pain and risk for SI in the moments when social threat occurs. We will conduct a longitudinal study of 200 youth ages 14–17 with recurrent musculoskeletal pain in limbs, back, or neck, which is common in adolescents and associated with suicide risk. We will recruit youth with a range of pain severity, but will oversample for high levels of pain to enrich for risk for SI. At baseline, youth will complete fMRI tasks to measure neural response to social threat. Youth will also participate in ecological momentary assessments of real-world fluctuations in social threat, pain, and SI over hours.