Evidence for anomalous lateralization across domain in ADHD children as well as adults identified with the Wender Utah rating scale

Two studies assessed the relation between ADHD symptomatology and correlates of cerebral dominance. In the first, laterality was examined in school children (N=57), 28 with ADHD. Parental reports of greater attentional symptoms were related to non-righthandedness, but teacher reports were related to anomalous laterality of foot, ear and eye, as well as hand. This suggests that the previously reported association between ADHD and non-righthandedness may not be unique, but instead indicative of a more general condition of anomalous lateralization. This possibility was examined in study two, in which 234 undergraduates were assessed. As expected, the 26 adults identified by the Wender Utah Rating Scale (WURS) as retrospectively reporting more ADHD characteristics were found to be generally male. Also, in a replication of study one, enhanced WURS scores were associated with anomalous lateralization beyond handedness. In this case, ADHD characteristics were associated with a shift away from a right bias for hand, foot, and ear, but not eye. Factor analysis of the extensive Steenhuis and Bryden handedness questionnaire was then undertaken to determine whether all aspects of handedness, or only a subset, are associated with ADHD. The factor analysis indicated that the retrospective reports of ADHD characteristics were associated with only two of the three dimensions. Though limitations such as the gender composition of the groups in study one tempers the conclusions, the results of both studies support previous findings that ADHD is associated with anomalous laterality, but also indicate that non-righthandedness is not an adequate characterization of this relationship.