Depressive symptoms amplify the impact of feeling supported or ignored online by friends on adolescents' well- and Ill-being.

Adolescents' communication with friends increasingly occurs online and research has primarily focused on the quantity rather than the quality of interactions, such as feeling supported or ignored. Since feeling supported or ignored by friends offline affects adolescents' well- and ill-being, it is essential to understand how these dynamics unfold in online contexts, particularly for adolescents with elevated depressive symptoms, who may be especially sensitive to these experiences. In this preregistered 100-day diary study, 479 adolescents (M age = 15.98, 54.9% girls; 96.9% Dutch) reported daily on time spent communicating online with friends, their experiences of feeling supported and ignored by friends, and their well- and ill-being. Results showed that time spent communicating online with friends did not relate to adolescents' well- and ill-being. Feeling supported by friends online resulted in higher well-being and lower ill-being, while feeling ignored by friends online was related to lower well-being and higher ill-being. Adolescents with elevated depressive symptoms experienced intensified effects, both positive and negative, suggesting more vulnerability to everyday online social experiences but also increased benefit from online support. Altogether, this underscores the importance for parents and clinicians to foster open conversations to help adolescents with elevated depressive symptoms navigate their digital social world.