PROJECT SUMMARY The purpose of this project is to examine social factors in the long-term mental health of young adults. Depression, anxiety, and loneliness have steeply risen among college and university students in the last decades, creating an enormous public health burden. Mental health difficulties promise to intensify during and after the COVID-19 pandemic, making it especially urgent to examine and amplify sources of resilience among young adults. Decades of evidence demonstrate that social connectedness, in the form of subjective belonging, objective social ties, and supportive interpersonal interactions, bolster mental health in several key ways. We propose that connectedness early in college, and students’ ability to regulate their emotions through social interactions, could play a pivotal role in encouraging long-term mental health. Though foundational, past work is limited in its ability to test these predictions because it typically examines (i) dyadic relationships rather than broader networks, (ii) the effect of small numbers of social factors, independently, and (iii) short time spans. These limitations are especially relevant to undergraduate settings, as student social life is centered in broad communities on which individuals depend for social support. This project will merge tools from social psychology, network analysis, and neuroscience to provide a rich, precise, and longitudinal account of how social connectedness supports young adult mental health over time. Our team has mapped the social networks formed by a large (n > 850) cohort of incoming university students, and combined this with ecological momentary assessment of students’ interactions and indices of mental health. We have found novel evidence that (i) “social microclimates,” such as the empathy of a student’s neighbors, affect individual well being, (ii) students search their social networks for supportive peers when under stress, (iii) peer interactions mitigate stress over time, and (iv) lonely students under-perceive close social ties, and under-utilize social resources. Here, we will expand this work in several ways. First, we will incorporate a longitudinal approach: measuring students’ connectedness and well being over their college career. We will combine these data with cutting-edge predictive modeling to quantify how social ties formed early in college relate to well being in later years, as well as students’ subsequent “mental health trajectories.” Second, we will recruit a longitudinal replication cohort to establish the robustness of our effects. Third, we will build on previous neuroimaging work of our team to probe neural “signatures” of social connectedness and examine their relationship to other measures of connection, and to well being, over time. At the level of basic science, this project will represent a novel, naturalistic approach to the study of social factors in mental health, and produce a large-scale, multifaceted dataset, which will be made publicly available to facilitate the collaborative and cumulative study of social connection. At a translational level, the resulting data can pave the way for policies aimed at fostering stronger social ties—and mental health—among a broad swath of the population.

PROJECT NARRATIVE Young adults face a striking levels of depression, anxiety, and loneliness, and though social factors—such as peer support—are likely pivotal to the mental health trajectories of young adults, existing work is limited in its ability to precisely quantify these long-term effects. This project will apply a unique combination of social network analysis, experience sampling, and neuroimaging in a large, longitudinal sample (two university cohorts) to examine (i) the formation of social communities among young adults, (ii) the effects of subjective, biological, and community-level indices of social connectedness on students’ mental health over their four-year college arc, and (iii) the role of relationships in sustaining well being during an acute, large-scale stressor—the COVID-19 pandemic. This work will sharpen basic science understanding of social factors in mental health, and pave the way for precise, novel interventions to bolster social connectedness and well being.