A Linguistic Approach Detects Stimulant Effects in Two Children with Attention-Deficit Hyperactivity Disorder

The acute effects of stimulant medication on the conversational language of children with attention-deficit hyperactivity disorder (ADHD) were investigated to determine the usefulness of a novel linguistic approach. A randomized placebo-controlled double-blind crossover single case design was used to study the effects of three doses (0.3, 0.6, 0.9 mg/kg) of methylphenidate and a placebo on the language used by two school-aged boys with ADHD during conversation with an adult. Two linguistic systems (speech function, cohesion), which describe the social use of language and simultaneously reflect cognitive processing, were selected for investigation. The psychostimulant led to both positive and negative changes in the socially appropriate use of language in the children's conversation. Findings are consistent with the postulated cognitive focusing effect of MPH, which can be therapeutic but in the extreme may produce overfocusing. These effects were linearly related to dose and were more pronounced in the child without concurrent anxiety disorders. Detailed linguistic analysis of the quality of spontaneous conversational interaction was useful in showing a dose-related effect of methylphenidate in ADHD. These dose-related effects reflect cognitive focusing and overfocusing that may both improve and impair social interaction in an individual at different times.