Attention-Deficit Hyperactivity Disorder (ADHD) versus Specific Learning Disorder-Reading Subtype (Dyslexia): performance in writing tasks

ABSTRACT Purpose: to analyze and compare the writing performance between students with attention-deficit/hyperactivity disorder (ADHD) and students with dyslexia. Methods: altogether, 27 children participated in the study, divided into the groups G-ADHD and G-Dyslexia. Their writing was assessed with a test that uses word and pseudoword dictation. The analysis addressed their writing level, word/pseudoword writing performance, and misspelling types. The groups were compared with the two-proportion z-test between two samples and the Mann-Whitney test (α = 0.05). Results: only one child in G-Dyslexia out of the 27 participating children was classified at the syllabic-alphabetical level. The others were classified at the alphabetical level, with no statistical difference between the groups in this item. The analysis of word/pseudoword writing performance revealed a difference between mean total scores, in which G-ADHD performed better. This group also had a higher percentage of children whose performance was classified as adequate for their age. There was a difference in misspellings between the groups in the omission of syllables, omission/addition of letters in complex syllables, and total performance - G-dyslexia made such errors more often. Conclusion: children with ADHD performed better in writing than the ones with dyslexia. However, writing cannot be used as a diagnostic marker between these conditions.