The impact of impairment criteria on rates of ADHD diagnoses in preschoolers.

Behaviors characteristic of ADHD are common among preschool children, and as such, their clinical significance is oftentimes difficult to ascertain. Thus a focus on impairment is essential in determining the clinical significance of these behaviors. In order to explore the impact of impairment criteria on rates of diagnoses in inattentive/hyperactive children aged 36 through 60-months-old, we first developed, and psychometrically evaluated, the Children's Problem Checklist (CPC) which was designed to assess psychosocial impairment associated with ADHD in a community sample of preschoolers (n = 394), and found its reliability and validity to be acceptable. We then examined the impact of the inclusion of various CPC-determined impairment criteria, over and above symptom criteria measured by the ADHD-RS-IV, using various cut points ranging from the 75th to 90th percentile of our community sample. This reduced the number of children meeting criteria for ADHD by 46-77%. These findings are discussed in terms of the importance of using impairment criteria, rather than just severity of inattention, impulsivity and hyperactivity, when diagnosing ADHD in preschool children.