The Impact of Problematic Smartphone Use on Behavioral and Neural Functioning

Presently, approximately 95% of U.S. teens now own smartphones giving rise to growing concerns about excessive and compulsive use patterns of use. Although smartphones offer unprecedented opportunities for learning and connection, problematic smartphone use (PSU), which affects roughly one in four adolescents, manifests as compulsive behavior that interferes with daily functioning and well-being. During this sensitive period of heightened neuroplasticity, PSU's behavioral patterns mirror other compulsive disorders, raising critical questions about its impact on adolescent development. The timing of PSU emergence coincides with a crucial period of neural and social development. During adolescence, smartphone-related disruptions can strain family relationships and weaken peer bonds, potentially compromising essential support systems. Physical health may also suffer as increased screen time increases sedentary behavior. These behavioral changes occur against the backdrop of significant brain maturation, particularly the asynchronous development of social-emotional systems and cognitive control networks. The constant stream of notifications and engaging apps may be especially disruptive to the frontoparietal network, which plays a vital role in attention regulation and inhibitory control. Although existing research has identified correlations between PSU and various negative outcomes, understanding the temporal dynamics and bidirectional influences of these relationships on adolescent development remains crucial. This study will address these gaps using complementary longitudinal approaches with a multimodal framework. The first project will follow adolescents (N=100) with mild to severe PSU (ages 13–18) over six months, using weekly experience sampling to examine fluctuations in PSU, social support, and physical activity. A cross-lagged panel model will assess bidirectional relationships and explore moderating factors, such as family and peer dynamics. The second project will leverage three waves of data from the Adolescent Brain Cognitive Development (ABCD) Study (N=4,754) to investigate how PSU influences changes in frontoparietal network connectivity over time, or conversely, whether neural connectivity patterns influence PSU. By exploring the interplay between PSU, social behavior, physical activity, and brain development, this research aims to delineate the temporal dynamics of PSU's developmental consequences and provide actionable insights for mitigating the negative impact. The findings will inform scalable interventions and evidence-based guidelines to support adolescent well-being. This work addresses a critical public health priority by advancing understanding of how digital behaviors shape development during this pivotal period of growth. Moreover, by identifying key periods of vulnerability and resilience, this research will establish a foundation for targeted interventions that promote healthy technology use while fostering crucial developmental milestones. Project Number: 1K25HD120751-01 | Fiscal Year: 2026 | NIH Institute/Center: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) | Principal Investigator: Nayoung Kim | Institution: COLUMBIA UNIVERSITY HEALTH SCIENCES, NEW YORK, NY | Award Amount: $132,300 | Activity Code: K25 | Study Section: Special Emphasis Panel[ZRG1 BP-V (91)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11282421