Abstract
We examine the current definition of ADHD and its subtypes and the diagnostic procedure described in the DSM-IV. The use of parent and teacher reports and behaviour rating scales in the diagnostic process is also evaluated. The value of more objective data sources, such as direct observations, simulated environments, and continuous performance tests is highlighted. We also describe the measurement of the three behavioural domains of ADHD – Inattention, Hyperactivity and Impulsivity – according to current theory and research. We suggest that greater attention to this literature will help the development of comprehensive, standardised performance tests that add precision to the assessment and diagnosis of ADHD and the ADHD construct itself.