Attention-deficit/hyperactivity disorder in preschool children: an investigation of validation based on visual attention performance.

OBJECTIVES The present study compared the performance of preschoolers who met Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition (DSM-IV) criteria for attention-deficit/hyperactivity disorder (ADHD) to those who did not meet these criteria on a test of visual attention. The aim was to investigate whether attentional impairments in preschoolers with DSM-IV ADHD could be detected, informing the nosology of preschool ADHD. METHODS A demographically diverse sample of n = 304 preschoolers, aged 3.0-5.11 years, was separated into two diagnostic groups: Those who met DSM-IV ADHD criteria and those who did not. Subtypes of ADHD were also examined. Parametric and nonparametric analyses were used to examine performance scores on accuracy, including errors of omission and commission. The sample was stratified into 3, 4-, and 5-year-old age groups. RESULTS Overall ADHD but not subtype-specific ADHD was associated with poor performance accuracy in the 4-year-old age group after controlling for gender and age. CONCLUSIONS Attentional impairments detected only in the 4-year-old age group suggest that DSM-IV ADHD criteria are useful and valid at this age. Study findings suggest modification to the DSM criteria may be needed for children younger than 4 and that further investigation of this issue using performance-based measures is now warranted.