Current controversy about diagnosis and treatment of attention deficit hyperactivity disorder (ADHD) reflects the divergence between developmental and non-developmental approaches. While there is growing evidence for biological vulnerabilities associated with ADHD, we believe that environmental factors, including early problems in parental attachment, are also important in determining the type and timing of deficit that a child develops, the risk to academic and social performance and eventual outcome. We warn against labelling children with ADHD simply because they fulfil the cross-sectional diagnostic symptom criteria of the Diagnostic and statistical manual of mental disorders - 4th edition (DSM-IV). We advocate an integrated biopsychosocial approach to diagnosis and management with a thorough developmental assessment to identify developmental factors, such as deficits in early attachment, contributing to the presentation.