Discrimination of attention deficit hyperactivity disorder by the continuous performance test

Objective: To investigate the Continuous Performance Test in discriminating a group of 56 attention deficit hyperactivity disorder (ADHD) children from 56 school children individually matched for age, sex and social class. Methodology: The children all completed the Continuous Performance Task (CPT). The mothers and teachers completed a Conners' Parent-Teacher Rating Scale for the clinic children. Results: The ADHD sample was selected so that the average IQ was 99.8 to match the school sample. A non-parametric discriminant function showed that the subtests of the CPT that best discriminated ADHD were age-normalized errors of commission (NCPTC) and age- normalized mean reaction time (NMNRT). Conclusion: Optimal use of the CPT for discrimination of ADHD should include age normalization and mean reaction time to targets. Further evoked potential studies may show brief cortical events involved in reaction time aver the course of the CPT, and the processes involved in behavioural control.