The effect of Methylphenidate-OROS® on the narrative ability of children with ADHD

Abstract

Background: The growing number of children diagnosed with attention deficit hyperactivity disorder (ADHD) underscores the importance of the role speech language pathologists play in addressing the language difficulties experienced by this population, including difficulties in narrative production, especially due to the close correlation between narrative performance and academic, as well as social, achievement. Although stimulant medication is the primary method of treatment for children with ADHD and is known to successfully address the behavioural and academic difficulties experienced by this population, few studies have focused on the effect of this medication on language difficulties. The need for speech-language services in the ADHD population is well documented in the literature, but it is not fully understood whether stimulant medication should be regarded as a replacement for, or an essential adjunct to speech language pathology services. Objectives: The goal of the current study was to investigate the effect of Methylphenidate-OROS® (MPH-OROS®) on the narrative ability of children with ADHD, through the analysis of microstructure and macrostructure elements. Research has shown that children with ADHD experience difficulty in planning, organizing, and monitoring narratives. The current study was based on evidence suggesting that MPH may improve aspects of language production through its effect on the primary symptoms of ADHD. Methods: A multiple single-subject pretest-posttest design was employed to examine the effect of MPH-OROS® on the narrative ability of children with ADHD. Wordless picture books were used to elicit narrative production as these books display the narrative structure valued by story grammar analysis (Stein & Glenn, 1979) while minimising the need for language comprehension and auditory memory capacity (McCabe, Bliss, Barra, & Bennett, 2008). Narratives were obtained from 12 children with ADHD (between the ages of 7 and 13 years). The children were presented with the wordless picture books for preview prior to the production of story narratives. The narratives were recorded and orthographically transcribed. For microstructure, narratives were coded using the Systematic Analysis of Language Transcripts (SALT) (Miller & Iglasias, 2012) coding conventions. Number of words, type-token ratio, and mean length of utterance were determined. For macrostructure, the narratives were analyzed and coded according to the Narrative Scoring Scheme (NSS) (Miller, Andriacchi, DiVall-Rayan, & Lien, 2003) which includes introduction, character development, mental states, referencing, conflict resolution, cohesion, and conclusion as well as a composite score reflecting the child’s overall narrative ability. Results: The administration of MPH-OROS® had a significant effect on aspects of language macrostructure, namely conflict resolution and cohesion, as well as overall narrative ability, based on the NSS total score. Little effect was noted, however, in microstructure elements. The effect of stimulant medication differed between participants, with particular differences noted in measures of productivity. MPH-OROS® increased productivity in certain participants while decreasing productivity in the remaining participants. Conclusions: The positive effect of stimulant medication on the macrostructure elements conflict resolution and cohesion as well as overall narrative ability, in the absence of an improvement in microstructure linguistic elements, suggests that the language difficulties experienced by this population may be due to difficulties in executive functions as well as inattention, hyperactivity, and impulsivity, all of which may have a negative impact on early language acquisition. While stimulant medication improves behaviours of attention and concentration, it cannot fully compensate for the poor structural and pragmatic language abilities, and the accompanying cascading effects, associated with the primary symptoms of ADHD. Therefore, a combination of treatments is advocated so as to ensure that children with ADHD are successful in reaching their full potential. In addition, the results highlight the possibility that response to stimulant medication may differ between ADHD-presentations, based on the presence or absence of the hyperactive component of ADHD.