Phenotyping sleep disturbances in ADHD and identifying harmonised outcome measures: A personalised precision medicine approach to disruptive behaviours.

Attention deficit hyperactivity disorder (ADHD) is a widespread neurodevelopmental disorder. Currently, the diagnosis and treatment of ADHD in children and adolescents is primarily centred on daytime functioning and the associated impairment of academic performance, although disrupted and restless sleep have been frequently reported in individuals with ADHD. Further, it has been recognised that sleep disorders not only intensify existing ADHD symptoms but in some cases can also mimic ADHD symptoms in the paediatric population with primary sleep disorders. Under the title ‘The blind spot: sleep as a child’s right issue?’, professionals from diverse disciplines, including medicine and social sciences as well as individuals with an interest in ADHD and sleep medicine, including laypeople, have initiated a unifying discourse. The objective of this discourse is to improve our understanding of the diagnosis and treatment of ADHD and disruptive behaviours and to develop personalised and precision medicine. Research has shown that the existing, primarily descriptive and categorical diagnostic systems do not capture the heterogeneous nature of youth with attentional and behavioural difficulties and the phenotypic expressions thereof, including nighttime behaviours and sleep. New strategies for clinical phenotyping and the exploration of patient-reported behaviours are necessary to expand our understanding and develop personalised treatment approaches. In this position paper, we outline gaps in the clinical care of ADHD and related sleep disturbances, review strategies for closing these gaps to meet the needs of individuals with ADHD, and suggest a roadmap for escaping the one-size-fits-all approach that has characterised ADHD treatment algorithms to date.