Abstract
OBJECTIVE: Irritability, anger, and aggression have garnered significant attention from youth mental health researchers and clinicians; however, fundamental challenges of conceptualization and measurement persist. This article reviews the evidence base for assessing these transdiagnostic constructs in children and adolescents. METHOD: We conducted a preregistered systematic review of the evidence behind instruments used to measure irritability, anger, aggression, and related problems in youth. Searches were conducted in PsycINFO and PubMed, identifying 4,664 unique articles. Eligibility criteria focused on self- and proxy-report measures with peer-reviewed psychometric evidence from studies in English with youths ages 3-18. Additional measures were found through ancillary search strategies (e.g. book chapters, review articles, test publishers). Measures were screened and coded by multiple raters with acceptable reliability. RESULTS: Overall, 68 instruments met criteria for inclusion, with scales covering irritability (n = 15), anger (n = 19), aggression (n = 45), and/or general overt externalizing problems (n = 27). Regarding overall psychometric support, 6 measures (8.8%) were classified as Excellent, 46 (67.6%) were Good, and 16 (23.5%) were Adequate. Descriptive information (e.g. informants, scales, availability, translations) and psychometric properties (e.g. reliability, validity, norms) are summarized. CONCLUSIONS: Numerous instruments for youth irritability, anger, and aggression exist with varying degrees of empirical support for specific applications. Although some measures were especially strong, none had uniformly excellent properties across all dimensions, signaling the need for further research in particular areas. Findings promote conceptual clarity while also producing a well-characterized toolkit for researchers and clinicians addressing transdiagnostic problems affecting youth.