Abstract
OBJECTIVE: Advances in developmentally sensitive measurement have enabled differentiation of normative versus clinically salient irritability in early childhood. However, clinical application of these measures is still nascent. The authors developed an optimized model of clinically salient irritable behaviors at preschool age. Based on this model, the authors derived an empirically based cutoff in relation to concurrent DSM-5 irritability-related disorders (i.e., oppositional defiant disorder, disruptive mood dysregulation disorder, other depressive disorders) and used longitudinal models to test the predictive validity of the cutoff for impairment and irritability trajectories and later DSM disorders. METHOD: Preschool children oversampled for irritability were followed over 3 time points into early school age (N = 425; mean age at baseline 4.7 years, mean follow-up 2.9 years). Mothers reported on children's irritability using the developmentally validated Multidimensional Assessment of Profile of Disruptive Behavior (MAP-DB) Temper Loss scale, impairment using the Family Life Impairment Scale, and DSM categories using the Preschool Age Psychiatric Assessment and the Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. RESULTS: Of 22 MAP-DB Temper Loss behaviors, 2 behaviors-1 normative (easily frustrated) and 1 rare dysregulated (destructive tantrums)-were uniquely related to cross-domain impairment. At baseline, these 2 irritability items identified diagnostic status (oppositional defiant disorder, disruptive mood dysregulation disorder, other depressive disorders) with good sensitivity (70-73%) and specificity (74-83%). Children above the irritability cutoff at baseline also exhibited more persistent irritability and impairment and greater likelihood of DSM disorders in early school age. CONCLUSION: Clinical identification of early-onset irritability can be enhanced using brief, developmentally optimized indicators. Further research to apply these findings to tiered early intervention is important.