Father, Mother, and Teacher Concordance and its Implications on Diagnosing ADHD and its Dimensions: A Twin Study

Background: In order to diagnose children with ADHD, the DSM-IV measures inattention (IA) and hyperactivity/impulsivity (HI) behavior in the context of significant impairment social and academic function. In order to diagnose, symptoms must be present in two different setting, which is commonly established in terms of home and school behaviors with the help of parent and teacher reports. Previous studies have found agreement to be low to moderate between mother-teacher. The question of whether father reports agree with mother and teacher reports has never been investigated. The aim of this study is to explore rater agreement across teacher, mother, and father ratings and also to study the potential differences in the importance of genetic and environmental influences of DSM-IV ADHD symptoms as assessed by mothers, fathers, and teachers. Method: Teacher, mother, and father questionnaire ratings of ADHD DSM-IV criteria ratings from a sample of 856 Swedish twin pairs aged 5-years olds were examined. Pearson correlations statistics allowed for assessment of rater correlation agreements. Twin methods were applied to investigate the extent to which raters differ in their assessment of genetic and environment influences for total ADHD behavior as well as for HI and IA. Results: Cross-correlations indicated low teacher-parent agreement. Sex differences in heritability were reported by fathers and were found to be due to differences in HI symptoms. There was also a possible indication of non-additive genetic influences for mother and father rated HI symptoms in females. Conclusion: Consistent with previous studies on rater assessment of ADHD in children, this study found that teacher-parent agreement was low when assessing for ADHD symptoms. This study also found evidence for significant sex differences as reported by fathers in the genetic and environmental contribution specifically in terms of reported hyperactive-impulsive behaviors; that is, genetic influences were of substantial importance for females, but not for males. As a consequence, shared environment was found to have a greater impact for ADHD behaviors in boys than girls when reported by fathers