Data fragmentation poses a significant challenge to advancing health equity in Puerto Rico. While national systems often exclude the territory, local datasets remain incomplete or siloed, limiting the ability to monitor mental health trends and design effective interventions. The ComPASS needs assessment highlighted this problem, documenting inconsistent access to reliable indicators such as school enrollment, child maltreatment, medication dispensations, and mental health service claims. To address these barriers, we developed the Mental Health Vulnerability Index for Minors (MHVI-M), a data-driven tool designed to enhance predictive capacity and support decision-making. The MHVI-M integrates multiple indicators across sectors—population demographics, health service utilization, medication data, abuse reports, and educational outcomes—into a composite index. Using machine learning (ML) and artificial intelligence (AI), the index predicts vulnerability patterns at the municipal level, identifying high-need areas and informing resource allocation. The design process was inherently transdisciplinary, involving psychologists, data scientists, engineers, and policy experts. The development of the MHVI-M also engaged community stakeholders to ensure that predictive insights aligned with contextual realities and local priorities. Early application of the index revealed significant geographic disparities in mental health vulnerability, with correlations to poverty, dropout rates, and rates of child abuse. Beyond its predictive function, the MHVI-M serves as the foundation for Puerto Rico's first curated mental health data hub. This hub promotes shared measurement approaches, fosters collaboration across agencies, and creates a platform for evidence-based policy agendas. By integrating psychological science with data innovation, the MHVI-M advances equity-oriented decision-making and offers a replicable model for other settings facing similar structural and informational barriers. This initiative demonstrates how applied psychology can bridge knowledge gaps, strengthen democratic participation, and generate systemic change.