Health Behaviors, Mental Health, and Peer Relationships in Adolescence: A Scoping Review

Adolescence is a critical developmental period marked by the interaction of health behaviors, psychosocial functioning, and peer relationships. This scoping review mapped quantitative evidence on the associations between health behaviors, emotional and behavioral problems, and peer-related factors among adolescents, accounting for sociodemographic characteristics. An electronic literature search was conducted in November 2025 using the ProQuest Summon Discovery Service, in line with PRISMA-ScR reporting guidance. Studies published between 2015 and 2025 that focused on adolescent populations and examined at least two key variables were considered; the included samples collectively spanned ages 10–18 years. Thirteen studies met the inclusion criteria. Across the included studies, health behaviors, particularly physical activity, diet, sleep, and screen use, were examined both individually and as co-occurring lifestyle patterns. Less favorable behavioral patterns were generally associated with poorer mental health and psychosocial indicators, whereas healthier patterns were associated with better well-being and quality of life. Associations with screen and internet use varied according to the type and intensity of digital engagement, with evidence of dose–response patterns for internet use and divergent associations across different screen activities. Peer relationships and related social factors were most often operationalized through social support, friendship quality, bullying, or victimization rather than through direct measures of peer attachment security. Within this limited and heterogeneous evidence base, supportive peer contexts were generally associated with more favorable behavioral and emotional outcomes, whereas bullying and victimization were associated with poorer outcomes. The mapped evidence is consistent with a biopsychosocial perspective but remains predominantly cross-sectional, underscoring the need for longitudinal research and more precise measurement of peer attachment processes.