Enhancing Irritability Assessment in Youth: Added Value of Capturing Temporal Dynamics and Daily Stressful Events

Abstract Objective Irritability is a common transdiagnostic symptom in youth that is associated with later psychopathology. Although it may both arise from and contribute to stressful experiences, this dynamic interplay is difficult to capture with retrospective questionnaires. Ecological momentary assessment (EMA) may complement person-level measures by assessing irritability and stressful events as they unfold in daily life. This study examined (1) the correspondence between momentary (EMA-based) and questionnaire-based person-level irritability and (2) bidirectional associations between momentary irritability and daily stressful events. Methods A community sample of 294 youth aged 12–21 years (M = 17.5; 58.5% female) completed self- and proxy-report irritability followed by a 14-day EMA protocol with eight daily assessments of irritability and stressful events. Dynamic structural equation modeling was used to examine cross-lagged within-person temporal associations and differences in these dynamics. Results Momentary and person-level irritability showed significant but modest correspondence. Most variance in momentary irritability occurred within rather than between individuals. Stressful events were consistently associated with higher irritability at the next timepoint. Youth with higher person-level irritability showed stronger increases in irritability following stressful events and greater within-person variability over time. By contrast, there was limited evidence for irritability being associated with later stressful events. Conclusions Irritability in youth appears to reflect both stable individual differences and context-dependent fluctuations in daily life. EMA may complement retrospective questionnaires by capturing stress-related increases and within-person variability, potentially informing more individualized assessment of irritability.