<italic>P</italic>-Factor(s) for Youth Psychopathology Across Informants and Models in 24 Societies.

ObjectiveMethodsResultsConclusionsAlthough the significance of the general factor of psychopathology (<italic>p)</italic> is being increasingly recognized, it remains unclear how to best operationalize and measure <italic>p</italic>. To test variations in the operationalizations of <italic>p</italic> and make practical recommendations for its assessment, we compared <italic>p</italic>-factor scores derived from four models.We compared <italic>p</italic> scores derived from principal axis (Model 1), hierarchical factor (Model 2), and bifactor (Model 3) analyses, plus a Total Problem score (sum of unit-weighted ratings of all problem items; Model 4) for parent- and self-rated youth psychopathology from 24 societies. Separately for each sample, we fitted the models to parent-ratings on the Child Behavior Checklist for Ages 6–18 (CBCL/6–18) and self-ratings on the Youth Self-Report (YSR) for 25,643 11–18-year-olds. Separately for each sample, we computed correlations between <italic>p-</italic>scores obtained for each pair of models, cross-informant correlations between <italic>p</italic>-scores for each model, and <italic>Q</italic>-correlations between mean item x <italic>p</italic>-score correlations for each pair of models.Results were similar for all models, as indicated by correlations of .973–.994 between <italic>p</italic>-scores for Models 1–4, plus similar cross-informant correlations between CBCL/6–18 and YSR Model 1–4 <italic>p</italic>-scores. Item x <italic>p</italic> correlations had similar rank orders between Models 1–4, as indicated by <italic>Q</italic> correlations of .957–.993.The similar results obtained for Models 1–4 argue for using the simplest model – the unit-weighted Total Problem score – to measure <italic>p</italic> for clinical and research assessment of youth psychopathology. Practical methods for measuring <italic>p</italic> may advance the field toward transdiagnostic patterns of problems. [ABSTRACT FROM AUTHOR]