PROJECT SUMMARY. In the United States, suicide is the second leading cause of death with approximately 7,000 suicides occurring annually among those aged 10-24. Critically, these numbers are rising among youth, and rates of serious suicidal thoughts and behaviors (STBs) are staggering, particularly among adolescent girls. Both theory and empirical research suggest that social factors play a putative role in risk for suicide among youth. Moreover, prior research implicates social communication – facial and non-facial cues exchanged during social interaction – in these social factors (e.g., connectedness). Yet, research examining fine-grained biobehavioral processes involved in social communication during interaction is extremely limited. The goal of this proposal, therefore, is to take a multiple-units-of-analysis approach to examine adolescent girls' social communication production and reception during actual social interactions, and determine whether alterations in biobehavioral processes involved in social communication directly and independently contribute to girls' subsequent (i) day- to-day social connectedness and (ii) STBs. An additional, exploratory aim will be to examine whether these biobehavioral processes indirectly impact girls' STBs through their effects on day-to-day social connectedness. Biobehavioral processes will include specific behavioral (i.e., eye-gaze and facial affect) and physiological (i.e., electrodermal activity [EDA] and pupil dilation) processes. Thus, this proposal will examine whether girls who demonstrate disrupted social communication (i.e., reduced eye-gaze, positive facial affect, and EDA reciprocity; attenuated gaze-contingent positive facial affect and EDA responses) will be less likely to exhibit future day-to- day social connectedness with parents and peers (Hypothesis 1). Next, this proposal will examine whether girls who demonstrate disruptions in the same biobehavioral processes involved in social communication will be more likely to report future STB onset (Hypothesis 2). Finally, exploratory analyses will examine day-to-day social disconnectedness as a potential mechanism through which deficits in social communication increase girls' STB risk. Participants for the proposed study will be adolescent girls drawn from an R01 grant, involving multimodal assessment during a laboratory-based parent-adolescent interaction task with girls (aged 11-13), follow-up ecological momentary assessment of day-to-day social connectedness two years later (aged 13-15), and STB assessments two (aged 13-15) and three years (aged 14-16) after the initial assessment. The sample size at baseline comprised 129 dyads, and 119 dyads were retained at the two-year follow up. Three-year follow-up assessments are ongoing. Under the guidance of leading experts in the field, training areas to facilitate future investigative independence include: ecological momentary assessment, mobile eye-tracking, longitudinal data analysis, and professional development. This type of nuanced, integrative research is essential to the identification of mechanisms of risk that can be therapeutically targeted to reduce STB risk during key windows of risk.

PROJECT NARRATIVE. Suicide is the second leading cause of death among those 10-34, and rates of suicidal ideation and attempts are higher among adolescent girls than boys. Although social processes are linked to suicide-related outcomes in adolescents, the role of biobehavioral processes involved in social communication in risk for suicide is unclear. The proposed study will advance our understanding of how these processes affect subsequent social connectedness and suicide risk in adolescent girls, which could provide specific, cost-effective, and accessible targets focused on enhancing social communication for prevention and intervention efforts.