Introduction: Although attention deficit hyperactivity disorder (ADHD) is usually associated with language disorders, there are few studies of phonological processing and the efficacy of psychostimulants (methylphenidate) on this.
Objective: 1. To find whether there are differences in the development of phonological processing, evaluated using linguistic segmentation tests and tests of lexical fluency with a phonetic mediator, between children with ADHD and normal children; and 2. To analyze the effects of methylphenidate on the phonological processing of children with ADHD.
Patients and methods: For the first objective, 37 children with ADHD and 37 normal children aged between 5 and 12 years were studied. Twenty were boys and 16 girls of lower middle class. Of these children, 18 of the ADHD and 18 of the normal group were studied for the second objective, 15 boys and 3 girls. Three different tests were used to evaluate aspects of phonological processing: induced phonological register, linguistic follow up and lexical fluency with phonetic mediation.
Results: Significant differences were found between the experimental and control groups when carrying out all types of phonological processing tasks. In the experimental group, with or without methylphenidate, improvement was seen in lexical fluency tasks whereas linguistic segmentation test improvement was limited.
Conclusions: These results show the importance of evaluating phonological processing in children with ADHD since this affects learning to read and write.