
Systematic review of 23 studies (2010–2024) on adolescents (ages 10–18) linking online social connection (structure, function, quality) with mental health. Findings highlight nuanced, bidirectional effects: online-only friendships can be protective (esp. for suicidal ideation), social capital in gaming linked to well-being, and gendered effects of active vs. passive use; perceived online support reduces depressed mood when received but can worsen mood if absent.