Background

Meghan A. Costello, Ph.D. is an Assistant Professor in the Department of Psychology’s School Psychology program at the University of South Carolina. Her work focuses on adolescent mental health and well-being, social relationships, and school- and community-based program development and evaluation.

Dr. Costello received her Ph.D. in Clinical Psychology with a concentration in Quantitative Psychology from the University of Virginia (UVA) and completed her predoctoral clinical internship in the cognitive behavioral scientist track at Massachusetts General Hospital/Harvard Medical School (MGH/HMS). She also received a certificate in Life Course Development from the International Max Planck Research Institute. Following her graduate training, Dr. Costello completed a K12 postdoctoral fellowship in collaboration with the Center for Addiction Medicine and the Center for School Behavioral Health at MGH/HMS.

Dr. Costello will be accepting students for the Fall 2027 admissions cycle in the School Psychology Ph.D. concentration.

Research

Dr. Costello’s research program investigates and leverages the role of social relationships in adolescent and emerging adult mental health. She is driven by the principle that interpersonal processes in adolescence and emerging adulthood are key for social and emotional development, and that adolescents themselves are the experts and therefore key research partners. Dr. Costello tackles questions about relationships and mental health through two related lines of inquiry.

1. The study of relationship processes as they naturally occur

   Through observational, longitudinal, and mixed-methods studies of peer, family, and romantic partner interactions, Dr. Costello seeks to understand how healthy social interactions, particularly emotional support processes among peers, develop, as well as how interactions among close relationship partners shape mental health and well-being in the immediate term and across time. Dr. Costello’s work in this domain thus far highlights that peer relationships in adolescence provide a space in which young people practice seeking and providing emotional support, which has implications for internalizing and externalizing symptomatology in the short term and sets the foundation for the skills and behaviors that they use with close others across the lifespan.

2. Community-engaged prevention program development

   By partnering with youth, schools, and their surrounding communities, Dr. Costello develops and evaluates scalable programming that leverages what we understand about the importance of peer relationships in adolescence and emerging adulthood. Dr. Costello’s work in this domain thus far includes developing The Connection Project, a peer-led belongingness intervention for high school and college students, in collaboration with Dr. Joe Allen’s team at UVA. Dr. Costello has also partnered with school systems across Massachusetts to evaluate substance use prevention and intervention programming, to track symptom development over time, and to investigate the role of peer network influence on intervention engagement and effectiveness.

Dr. Costello prioritizes uplifting equity and belonging in her research, teaching, mentorship, and clinical work. As such, she believes in scholarly activism, community engagement, and connection to public policy experts. Across all dimensions of her work, she is driven by the principle that the work must be grounded in the potential to provide meaningful benefit to the community partners and participants who make it possible.

Representative Publications

1. Costello, M.A., Pettit, C., Hellwig, A.F., Hunt, G.L., Bailey, N.A., & Allen, J.P. (2024). Adolescent Social Learning Within Supportive Friendships: Self-Disclosure and Relationship Quality from Adolescence to Adulthood. Journal of Research on Adolescence, 34(3), 805-817. https://doi.org/10.1111/jora.12947
2. Costello, M.A., Crocker, J., Kaur, J., Du, R., Oxendine, E., Greenspan, L., Butler, R., & Schuster, R.M. (2026). Exploring a Low Burden, Universally Administered Strategy to Connect Adolescents to School-Based Mental Health Supports. School Psychology. https://doi.org/10.1037/spq0000719
3. Costello, M.A., Nagel, A.G., Hunt, G.L., Rivens, A.J., Hazelwood, O.A., Pettit, C., & Allen, J.P. (2022). Facilitating Connection to Enhance College Student Well-Being: Evaluation of an Experiential Group Intervention. American Journal of Community Psychology, 70(3-4), 314-326. https://doi.org/10.1002/ajcp.12601
4. Costello, M.A., Brehm, M., Rivens, A.J., Hunt, G.L., Nagel, A.G., & Allen, J.P. (2025). Support-seeking About Social Relationships with Friends is Associated with Friendship Quality, Emotional Support, and Self-Disclosure in Adolescence. Journal of Social and Personal Relationships, 42(12). https://doi.org/10.1177/02654075251371391
5. Costello, M.A., Allen, J.P., Womack, S.R., Stern, J.A., Loeb, E.L., & Pettit, C. (2023). Characterizing Emotional Support Development from Adolescent Best Friendships to Adult Romantic Relationships. Journal of Research on Adolescence, 33(2), 389-403. https://doi.org/10.1111/jora.12809
6. Costello, M.A., Pascale, M., Potter, K., Knoll, S.J., Bodolay, A., Kaur, J., Du, R., Greenspan, L., Gray, C.A., McIntyre, J., & Schuster, R.M. (2025). Understanding Adolescent Mental Health Symptom Progression in School-Based Settings: The Substance Use and Risk Factors (SURF) Survey. School Psychology, 40(6), 666-679. https://doi.org/10.1037/spq0000681