Friendships in flux: A daily examination of friend continuity and associations with adolescent mood.

Although maintaining stable friendships is an important developmental task for adolescents, there is limited understanding of whether adolescents' friendships vary from day to day and predict changes in emotional well-being. Therefore, the current daily diary study aimed to characterize the day-to-day consistency of adolescents' close friendships and investigate whether feeling close to the same friends from 1 day to the next (daily friend continuity) predicted daily mood. Fourteen consecutive days of friendship nominations and mood assessments were collected from 195 11^th-grade students (M_age = 16.48; SD_age = 0.53; 66% female). Variability statistics (intraclass correlations, root mean square of successive differences) indicated considerable fluctuations in the consistency of friendship closeness as perceived by adolescents across 2 weeks. Results from multilevel models demonstrated that greater friend continuity was associated with greater positive mood, but not negative mood, at both the within- and between-person level. The findings reveal inconsistency in whom adolescents feel closest over 2 weeks and suggest that maintaining closeness with the same friends from 1 day to the next bolsters adolescents' short-term emotional well-being. (PsycInfo Database Record (c) 2025 APA, all rights reserved).