Peer-reviewed article

Assessing the feasibility and acceptability of a school-based non-pharmacological intervention for ADHD: the Flex toolkit.

Russell AE, Holt S, Kelman C, Ford T, Moore D et al. · 22 Jul 2026

Abstract

Background Attention deficit/hyperactivity disorder (ADHD) is a prevalent and impairing neurodevelopmental disorder. Traits cause impairment for 5-10% of children. School is a particular challenge for children with ADHD, who are at risk of exclusion, mental health problems and poor attainment. Existing school-based interventions have evidence of effectiveness, however are not implementable in UK mainstream school contexts due to resource constraints. We co-designed an individualised novel non-pharmacological intervention for ADHD (the Flex toolkit) based on principles of behaviour change, using Intervention Mapping. We aimed to assess the feasibility and acceptability of the Flex toolkit, and assess whether a definitive evaluation in schools is feasible. Methods A multiple baseline case series study was conducted with eight UK primary schools. Teachers, parents and children completed both quantitative and qualitative measures over 1 year, with the intervention being used for approximately 16 weeks. Mixed methods analysis was used to assess feasibility and acceptability, and evidence for perceived impact of the intervention on relevant outcomes as well as mechanisms of action from the intervention logic model was assessed. Results Forty children with ADHD, 53 teachers and 49 parents/caregivers participated. The intervention was deemed to be highly acceptable and useful; however, it was not feasible for staff to implement with fidelity in schools as an unguided intervention. Those who engaged with the intervention often perceived it to have beneficial impacts for study children as evidenced in qualitative data. The research design was considered to be both acceptable and feasible with some recommendations to streamline procedures for a definitive trial. Conclusions The Flex toolkit is acceptable to schools. It was perceived to improve a range of outcomes that relate to dimensions of mental health and school-based impairment; however, the study was not powered to detect quantitative change. A definitive evaluation would need to test a supported delivery model of the intervention to ensure that it is delivered with fidelity; we recommend a "coach" whose role would be to provide light-touch support to teachers to select and implement intervention components. The research design for a definitive evaluation can mirror many of the aspects of the feasibility study design.