Interpersonal Stress, Social Media, and Risk for Adolescent Suicidal Thoughts and Behaviors - Project Summary Over the past 15 years, suicide rates among adolescents have increased ~60%. Recently, problematic social media use has been linked to the emergence of suicidal thoughts and behaviors (STB), perhaps reflecting greater interpersonal stress exposure. Understanding the type, timing, and severity of interpersonal stress exposure is critical to understand STB risk, which requires carefully characterizing exposures present in their digital lives through a deep interrogation of real-time interactions within social media. In line with the Stress Generation Framework, adolescents experiencing psychiatric disorders possess characteristics that increase the occurrence of interpersonal stress, which may include negative social media exposures. Accordingly, this project will identify social neural susceptibilities that may increase the occurrence of negative social media exposures and examine physiological processes that are impacted by negative social media exposures over time. Our study will include adolescents ages 14-17 (N=300), which will be oversampled for youth at high risk for suicide (n=200), defined as STB in the past 3 months and/or a past-year suicide attempt. Additionally, we will recruit adolescents with psychiatric disorders but without a lifetime history of STB (n=100), providing an opportunity to identify biological markers and temporally refined social media exposures that characterize risk for STB as opposed to identifying risk factors that associate with psychiatric disorders more broadly. Comprehensive clinical assessments will be completed at baseline, and additionally, we will probe past-year user-generated content to assess dynamic changes in negative exposures to characterize core interpersonal processes across social media platforms, including: (a) online victimization (e.g., harassment, hate speech), (b) reduced social capital (e.g., reduced social network size), and (c) reduced social support (e.g., reduced engagement, reciprocity of messaging). We also will collect baseline fMRI neural responses characterizing social processes and assess chronic HPA axis activity. At the 2-, 4-, and 6-month follow-up assessments, interviews, social media data, HPA axis activity, and self-reports will be re-assessed. The overarching goals is to examine the relationship between biological processes and social media exposures, particularly with regards to elucidating suicide risk. First, we will test whether social neural network alterations increase susceptibility to negative social media exposures. Second, we will test whether negative social media exposures negatively impact HPA axis activity. Last, we will test whether negative social media exposures, social neural alterations, HPA axis activity, and their interactions lead to the emergence of suicide events (i.e., actual, interrupted, or aborted attempts; active suicidal ideation with method, intent, or plan; emergency department visits or psychiatric hospitalizations for STB). Through this comprehensive approach, we will address a critical public health initiative by identifying those who are susceptible to negative social media exposures, and providing actionable markers to reduce the needless loss of life among young people.