ADHD expressive writing difficulties of ADHD children: when good declarative knowledge is not sufficient

A large body of evidence shows that many of the academic difficulties Attention Deficit Hyperactivity Disorder (ADHD) children have may be related to their problems in executive control. However, the particular case of expressive writing has not been deeply explored. The present study examines the typical school exercise of writing a letter. Participants were 33 third, fourth, and fifth graders referred by teachers for the presence of ADHD symptoms plus 33 controls. The task consisted of describing an aspect of their life in the form of a letter. Texts of ADHD children were poorer than those of the controls for structure, vocabulary, grammar, length, and accuracy. Furthermore, the difference persisted even when a guide was used to support the writing task. However, the two groups were not significantly different in a metacognitive test measuring knowledge on critical factors affecting expressive writing. Results show that ADHD children may encounter severe difficulties in expressive writing that are not due to differences in knowledge about how to write. Educational implications are discussed.