An increasing number of children and adults are receiving a diagnosis of Attention Deficit/Hyperactivity Disorder (ADHD). Pharmacological intervention (particularly stimulant medication) is considered the 'gold standard' approach to supporting the functional impact of the condition. Speech pathologists can play a vital role in supporting people with ADHD, so it is imperative that we understand the impact of pharmacological treatment on language and communication. In this presentation, we will present insights into changes in oral and written language skills associated with the mechanisms of stimulant and non-stimulant medication and identify gaps in the literature. We followed contemporary systematic review methodology to synthesise the literature that explicitly tested the effect(s) of medication on oral and/or written language outcomes in children and adults with ADHD. Twenty empirical papers were included in the review. Generally, results indicated an inconsistent effect of medication on language skills. Where effects were reported, they appeared to reflect the positive impact of enhanced attention and focus on performance during complex language tasks, as opposed to improvement in underlying language capacity. The evidence base comprises a dominance of investigations into the effect of stimulant medication on reading in children with ADHD. Conversely, the effect(s) of stimulant or non-stimulant medication on a range of expressive and receptive language skills, across modalities, has received little attention; particularly in adults with ADHD. These gaps have a significant impact on our understanding of the functional impact of pharmacological intervention on language and communication in ADHD across the lifespan. Our presentation will underscore the critical need for further investigation in this area. We will discuss clinical, theoretical, and empirical implications of this work.

1. The literature reports inconsistent effects of pharmacological intervention on oral and written language skills in people with ADHD. The outcomes of this review indicate that, where effects of medication are observed, they generally reflect an improvement in focus and attention during language tasks that have greater cognitive and linguistic demand (e.g., passage comprehension). Conversely, greater inconsistency is observed when discrete language skills (e.g., receptive vocabulary) are assessed using domain-specific tasks. Medication, therefore, appears to benefit the application of language knowledge and skill during functional tasks, as opposed to enacting change on underlying language capacity or knowledge. Additionally, clinicians may be better placed to detect the impact of clients' medications using more complex language assessments.
2. The evidence base is dominated by studies investigating the impact of stimulant medication on written language skills in children with ADHD. Given the increasing rate of ADHD diagnosis across the lifespan, it is critical that the effect of medication on a range of language and communication outcomes is explored.
3. The literature is fraught with methodological and terminological inconsistency related to the assessment and definition of language constructs, respectively. This limits the ease with which studies can be synthesised and meaningful conclusions regarding the impact of medication on language in ADHD can be drawn. Our review calls for greater consistency in assessment and definition of key constructs in this space to inform a more comprehensive understanding of the functional impact of medication on language in this population.