Associations of Anxiety and Depression and Hypomanic Traits with Self-Informant Discrepancies in Adults First Diagnosed with ADHD in Adulthood: A Cross-Sectional Study

Background/Objectives: Adults first diagnosed with ADHD in adulthood are a clinically distinct subgroup, yet the factors associated with self-informant discrepancies in this group remain underexplored. This study examined the associations of anxiety, depression, and hypomanic traits with self-informant discrepancies on the DIVA-5. Methods: A total of 217 adults first diagnosed with ADHD in adulthood and their parents independently completed the DIVA-5. Patients also completed the Self-Rating Depression Scale (SDS), Self-Rating Anxiety Scale (SAS), and the 32-item Hypomania Checklist (HCL-32). Associations were examined using Spearman correlations, group comparisons, and hierarchical linear regression, controlling for demographic covariates. All reported p-values were adjusted using the Benjamini–Hochberg false discovery rate method. Results: Self-informant discrepancies were significant across all symptom and functional impairment domains, with self-ratings consistently higher than parent-ratings. Anxiety showed robust independent associations, particularly for hyperactivity-impulsivity (both childhood and adulthood) and childhood functional impairment. Depression showed positive associations only in separate hierarchical linear regression analyses for each affective characteristic; these associations were no longer significant after controlling for anxiety. Hypomanic traits were not independently associated with self-informant discrepancies in any domain. Conclusions: Among adults first diagnosed with ADHD in adulthood, anxiety was robustly associated with self-informant discrepancies, whereas depression and hypomanic traits were not. These findings underscore the importance of attending to anxiety when interpreting self-informant discrepancies in this population.