Prevalence, stability, and predictive utility of the Multidimensional Assessment of Preschoolers Scales clinically optimized irritability score: Pragmatic early assessment of mental disorder risk

OBJECTIVES: Characterizing the scope and import of early childhood irritability is essential for real‐world actualization of this reliable indicator of transdiagnostic mental health risk. Thus, we utilize pragmatic assessment to establish prevalence, stability, and predictive utility of clinically significant early childhood irritability. METHODS: Data included two independent, diverse community samples of preschool age children (N = 1857; N = 1490), with a subset enriched for risk (N = 425) assessed longitudinally from early childhood through preadolescence (∼4–9 years old). A validated, brief (2‐item) scale pragmatically assessed clinically significant irritability. In the longitudinal subsample, clinical interviews assessed internalizing/externalizing disorders. RESULTS: One in five preschool‐age children had clinically significant irritability, which was independently replicated. Irritability was highly stable through preadolescence. Children with versus without clinically significant early childhood irritability had greater odds of early onset, persistent internalizing/externalizing disorders. The pragmatic assessment effectively screened out low‐risk children and identified 2/3 of children with early‐onset, persistent psychopathology. CONCLUSIONS: Clinically significant early childhood irritability prevalence is akin to the pediatric obesity epidemic and may warrant similar universal screening/intervention. Also, irritability's stability demonstrates the common guidance “they'll grow out of it” to be false. Finally, pragmatic irritability assessment has transdiagnostic predictive power and addresses a need for feasible measures to flag risk.