Parental ratings of preschoolers' risk for injury, direct assessment of preschoolers' behavior thought related to risk for injury (e.g., Inattention, impulsivity) and number of documented injuries were examined in preschoolers with Attention Deficit Hyperactivity Disorder (ADHD) and their non-ADHD peers (Control). Of preschoolers with ADHD, 58.3% exhibited behavior which placed them at-risk for physical injury (0% Control), and their performance was significantly poorer on clinic-based tests. Nonetheless, preschoolers with ADHD did not actually sustain significantly more injuries which warranted medical treatment in an emergency department. Although preschoolers with ADHD may be at increased risk for minor injuries, further research is needed to determine whether they more frequently sustain more serious injuries.

In the present study, 50 preschoolers were formally and independently classified using both the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and third edition-revised (DSM-III-R) criteria for attention-deficit hyperactivity disorder (ADHD). The sample consisted of 25 preschoolers classified as having ADHD and 25 typically developing preschoolers for comparison; the sample was matched on gender, age, and socioeconomic status. All 50 preschoolers were without neurologic or neurodevelopmental disorders, oppositional defiant disorder, or language delay. There were four key findings: first, of the 25 preschoolers with ADHD, DSM-IV classification was as follows: hyperactive-impulsivity type (68%), combined type (28%), and inattentive type (4%). Second, the DSM-IV profiles showed that several symptoms were either infrequently endorsed by parents, reflecting limited applicability to preschoolers with ADHD, or frequently endorsed by parents of typically developing preschoolers, thus reducing their diagnostic value. Third, of the 25 preschoolers classified as having ADHD using DSM-IV criteria, 16% would not have been classified as having ADHD using the DSM-III-R criteria. The DSM-IV criteria therefore appear to be more lenient than the DSM-III-R criteria for this age group. Fourth, two symptoms that were not included in the DSM-IV, but were part of the DSM-III-R, were found to have clinical value for differentiating preschoolers with ADHD from their typically developing peers.

Sixteen preschoolers, (8 with Attention-Deficit/Hyperactivity Disorder [ADHD], 8 matched controls) were assessed twice, 5 months apart. Preschoolers with ADHD were rated by their parents as significantly more inattentive, exhibited more behavior problems, fewer age-appropriate social skills, made more errors of omission on both the visual and auditory attention tests, and more errors of commission on both the visual attention and the visual-search cancellation tests. Preschoolers with ADHD were then treated with stimulant medication and exhibited improved behavior as well as significantly reduced errors of omission on visual and auditory preschool vigilance tests, and fewer errors of commission on the visual-search preschool cancellation test. Developmentally appropriate direct measures of attention, in conjunction with parental ratings of child behavior, can be used to assess the efficacy of pharmacological treatment of preschoolers with ADHD.

To test the validity of a new computerized task to assess children's receptive vocabulary, event-related potentials (ERPs) were recorded from 56 typically developing children ranging in age from 5 to 12 years. This ERP-computerized vocabulary task does not require a child to give a verbal or motor (i.e. pointing) response. Single pictures, from an existing standardized test of receptive vocabulary, were presented on a computer screen and simultaneously named either correctly (congruent) or incorrectly (incongruent) via a computer. As predicted, the N400 amplitude was found to be significantly higher to the incongruent picture-word pair (i.e. the child knew it was an incorrect pairing) than to the congruent picture-word pair (i.e. the child knew it was a correct pairing). This effect was found for each of the four age groups (5 to 6 years, 7 to 8 years, 9 to 10 years, 11 to 12 years). This task accurately estimated current receptive vocabulary in typically developing children. Although still in the development stage, it may eventually serve as an adjunct to a thorough neurological and neurodevelopmental assessment of some children presenting with moderate to severe cerebral palsy.