Measuring Youth Mental Health Vulnerability Across Communities: Development and Validation of ThriveAtlas

CONTEXT: Youth mental health is shaped by interacting individual, relational, and structural factors that vary across communities, yet few tools integrate these drivers into youth-specific, geographically granular measures for decision-making. OBJECTIVE: This study describes the development and preliminary validation of ThriveAtlas, a geographically granular index designed to identify factors that prevent youth from thriving. DESIGN: ThriveAtlas was developed through a multistep process including a targeted literature review; selection and construction of indicators from public and proprietary data sources; aggregation into thematic domains and a composite index; and preliminary validation using county-level mental health outcomes. SETTING: County-level analysis using school-based survey data from California (California Healthy Kids Survey, 2021-2023). PARTICIPANTS: Ninth-grade students across 53 California counties. MAIN OUTCOME MEASURE: County-level principal components derived from 5 self-reported mental health indicators; prioritization overlap with the Social Vulnerability Index (Jaccard statistic); and univariate explanatory power (R2) of ThriveAtlas domains versus Social Vulnerability Index (SVI) domains. RESULTS: The review identified key gaps in existing tools: youth-focused indices often emphasize general well-being rather than mental health, while structurally focused indices lack youth specificity or substate granularity. ThriveAtlas revealed geographic variability in vulnerability, including regional clusters and isolated high-risk counties. Validation analyses showed expected patterns in California, where higher vulnerability aligned with greater distress and lower well-being. ThriveAtlas and SVI were correlated (Spearman ρ = 0.66) across California counties; however, ThriveAtlas themes better explained county-level mental health outcomes than SVI domains (R2 = 0.41 vs. 0.27), and the 2 tools agreed on only one-third of high-priority counties (Jaccard = 0.33). CONCLUSION: ThriveAtlas addresses a critical measurement gap by providing a youth-centered, multidimensional, and geographically granular index of vulnerability. Early validation supports its utility as a decision-relevant signal to identify communities with elevated youth mental health challenges and inform targeted intervention strategies.