Objective:Interpersonal functioning is a core area of impairment for young adults with Attention-Deficit/Hyperactivity Disorder (ADHD), yet the assessment of their interpersonal problems has not been approached using a comprehensive model of interpersonal behaviors. Method: Interpersonal problems of young adults with ADHD (n = 24) were compared to non-ADHD peers (n = 26) by self- and collateral-report using the Inventory of Interpersonal Problems-Circumplex-Item Response Theory (IIP-C-IRT). Results: Both self- and collateral-reports yielded significantly higher scores across interpersonal problem domains, except for self-reported Hostile-Dominant (HD) interpersonal problems. Discrepancy scores between self- and collateral-report supported larger differences in the ADHD versus non-ADHD groups for HD problems. Large correlations between collateral-reported family relationship impairments and HD problems were found only for the ADHD group. Conclusion: Young adults with ADHD have higher levels of interpersonal problems relative to their non-ADHD peers, but also appear to underreport HD interpersonal problems relative to non-ADHD peers, suggesting the presence of a bias. (J. of Att. Dis. XXXX; XX[X] XX-XX).
Keywords: ADHD; assessment; interpersonal problems; positive illusory bias; young adults.