Objective: Rates of adolescent mood disorders and adolescent smartphone use have risen in parallel, leading some to suggest that smartphone use might have detrimental effects on adolescents' moods. Alternatively, it is possible that adolescents turn to smartphone use when experiencing negative mood. The purpose of this study was to explore the relationship between adolescent smartphone use and mood using a longitudinal methodology that measured both in real-time.

Method: This study used an Ecological Momentary Assessment (EMA) procedure completed by 253 12-17-year old participants from across the United States. Participants received short surveys delivered to their smartphones at random points throughout the day. Measures included real-time, in-situ assessments of smartphone use, current mood, and mood before smartphone use.

Results: Based on tests of a multilevel regression model, adolescent moods were positively associated with smartphone use (β = 0.261, F(1,259.49) = 19.120, p < 0.001), and that mood was positively associated with the length of phone use sessions (length of phone use β = 0.100, F(1, 112.88) = 5.616, p = 0.020). Participants also reported significant changes in mood during phone use, such that moods before phone use were significantly lower than moods during phone use (MChange = 0.539, t(2491) = 23.174, p < 0.001). Change in mood (mood before minus mood during phone use) was positively associated with the length of smartphone use sessions (β = 0.097, F(1,122.20) = 4.178, p = 0.043), such that participants who had a higher change in mood were more likely to report a longer length of smartphone use.

Conclusions: Findings suggest that adolescent smartphone use is positively associated with mood. This finding may suggest that adolescents use smartphones for mood modification, which aligns with an understanding of smartphone use as potentially addictive behavior.