Trajectory of emotion dysregulation in positive and negative affect across childhood predicts adolescent emotion dysregulation and overall functioning.

Emotion dysregulation is cross-diagnostic and impairing. Most research has focused on dysregulated expressions of negative affect, often measured as irritability, which is associated with multiple forms of psychopathology and predicts negative outcomes. However, the Research Domain Criteria (RDoC) include both negative and positive valence systems. Emerging evidence suggests that dysregulated expressions of positive affect, or excitability, in early childhood predict later psychopathology and impairment above and beyond irritability. Typically, irritability declines from early through middle childhood; however, the developmental trajectory of excitability is unknown. The impact of excitability across childhood on later emotion dysregulation is also yet unknown. In a well-characterized, longitudinal sample of 129 children studied from ages 3 to 5.11 years through 14 to 19 years, enriched for early depression and disruptive symptoms, we assessed the trajectory of irritability and excitability using multilevel modeling and how components of these trajectories impact later emotion dysregulation. While irritability declines across childhood, excitability remains remarkably stable both within and across the group. Overall levels of excitability (excitability intercept) predict later emotion dysregulation as measured by parent and self-report and predict decreased functional magnetic resonance imaging activity in cognitive emotion regulation regions during an emotion regulation task. Irritability was not related to any dysregulation outcome above and beyond excitability.