Because you had a bad day: General and daily relations between reactive temperament, emotion regulation, and depressive symptoms in youth.

Negative emotionality (NE) and positive emotionality (PE) have repeatedly shown to act as vulnerability factors for youth depression. Less research examined the mechanisms through which these reactive temperament traits may differently confer vulnerability to depression. Based on recent integrated models of depression proposing emotion regulation as a key underlying mechanism, the current study aimed to clarify the general and day-to-day relations among temperament, emotion regulation strategies, and depressive symptoms in Dutch-speaking youth (35% boys; Mage = 13.27 years, SD = 1.98) using a cross-sectional (n = 495) and a 7-day daily diary design (n = 469). Self-reported temperament, trait rumination, trait positive refocusing, and depressive symptoms were measured at baseline. State rumination, state positive refocusing, and depressive symptoms were further assessed daily. Whereas results revealed that NE and PE interacted in predicting baseline and daily depressive symptoms, the cross-sectional analyses provide preliminary evidence for the hypothesis that NE and PE each provide unique pathways for understanding vulnerability to depression. Additional analyses in the daily diary study showed NE to be significantly related to trajectories of state rumination. Results contribute to a more nuanced understanding of the associations between temperament, emotion regulation strategies, and depressive symptoms in youth.