Abstract
ADHD is a common neurodevelopmental disorder that is associated with pervasive negative long-term outcomes including decreased social, academic/occupational, and daily functioning; as well as comorbid psychological disorders. In order to effectively treat this disorder, and decease the associated deficits, it is important to understand the possible contributing mechanisms of this disorder. There are numerous contributors to the functioning of individuals with ADHD. Two key factors are temperament and cognitive functioning. Temperamental traits, including negative emotionality and cognitive difficulties have been widely associated with ADHD and past studies have found that cognition moderates the effects of temperament on ADHD symptom severity. The present study aimed to examine the unique and integrated effects of negative emotionality and cognitive functioning on ADHD symptom severity within primary school aged children. Participants were 132 children between 6 and 12 years old. Parent and teacher ratings of executive functioning and negative emotionality were obtained from standardised measures and children’s neurocognitive abilities were objectively measured. Results supported both a unique and integrated effect of temperament and cognition on the outcome of ADHD. Specially, correlational analyses found that lower neurocognitive abilities/executive functioning and higher negative emotionality are associated with higher ADHD symptom severity. Furthermore, executive functioning and processing speed moderated the effects of negative emotionality on ADHD symptom severity. These moderation effects were consistent with those found in Healey et al’s (2011) study. These findings are discussed in regards to their theoretical and practical implications and further areas of research are proposed.