This paper is a contribution to the debate on the phenomenon of Attention Deficit Hyperactivity Disorder (ADHD). It explores how and why the discourses surrounding the aetiology and interventions are dominated by a bio-medical understanding of ADHD. Competing discourses are examined, particularly those marginalised because they do not support the prevailing neurological paradigm of ADHD. The reasons for the controversy over psychostimulant medications are explored by examining the reasoning and evidence which contribute to the medicalisation of behaviour. Given the uncertainties, possible contradictions and ambiguities within the bio-medical model of ADHD, educational professionals would do well to look beyond the label to the child's needs rather than assume that such a condition "exists" and is the provenance of those in the medical profession. (Contains 1 note.)