Do Internalizing Syndromes have Incremental Validity for External Criteria Above and Beyond Each Other?

Given robust support for internalizing psychopathology as a broad construct, the field has shifted focus from its specific subcomponents to studying internalizing overall, leaving it unclear whether its components provide additional information. We investigated whether internalizing syndromes have incremental validity beyond each other in their associations with 22 external criteria (e.g., health, functioning) using the National Epidemiological Survey on Alcohol and Related Conditions data, a representative adult sample (Wave 1, N=43,093). We extracted a five-factor model for 5 lower-order internalizing syndromes (generalized anxiety, major depression, social anxiety, specific phobia, panic). All were moderately correlated with each other and associated with external criteria. Adjusting for other internalizing syndromes, generalized anxiety, major depression, and panic syndromes demonstrated incremental validity, or unique associations with external criteria. Our findings suggest internalizing syndromes exhibit shared and unique features. Investigating both the internalizing spectrum and its more specific syndromes can offer deeper insights into psychopathology.