The YAQ-S and YAQ-I: the development of self and informant questionnaires reporting on current adult ADHD symptomatology, comorbid and associated problems

The purpose of this paper was to investigate the factor structure and reliability of the Young ADHD Questionnaire-Self-Report [YAQ-S] and the Young ADHD Questionnaire-Informant Report [YAQ-I] and to investigate the relationship between self and informant reported information. A second aim was to evaluate whether the questionnaires discriminated between an ADHD symptomatic group [ADHD], a clinic referred non-ADHD symptomatic group [CCG] and a healthy control group [NCG]. A total of 223 participants and 150 informants (recruited from clinic referrals and healthy community controls) completed the questionnaires. A principal component analysis was conducted on the data and four factors were rotated using varimax procedure relating to ADHD symptoms, emotional problems, delinquency and social functioning. Comparison of factors across the three groups showed the ADHD group had significantly greater ADHD symptomatology, emotional problems and delinquent behaviour than the CCG and the NCG on both the YAQ-S and YAQ-I. Social functioning was impaired compared with the NCG but not the CCG. All factors significantly correlated between the YAQ-S and YAQ-I except for the social functioning of the ADHD group and the ADHD symptom scale for all three groups. Discriminant function analysis showed the ADHD scale to be the most significant factor between groups according to self and informant ratings. The findings suggest that the instruments are useful clinical assessment tools for guiding treatment.