Comparison of the Wechsler Preschool and Primary Scale of Intelligence-Third Edition and the Leiter-R Intellectual Assessments for Clinic-Referred Children.

A review of clinical records was conducted for children with developmental, emotional, and behavioral difficulties who were assessed with both the Wechsler preschool and primary scale of intelligence-third edition (WPPSI-IIICDN; Wechsler, 2004) and the Leiter international performance scale-revised (Leiter-R; Roid & Miller, 1997) within the same psychological evaluation. Forty children, ages 3-7, were included in this study. Pearson correlations showed that the IQ scores of the two instruments are strongly related (r > .70; p < .001). However, paired t-tests showed that overall Leiter-R scores (M = 99.03) were significantly higher than WPPSI-IIICDN scores (PIQ; M = 82.28, FSIQ; M = 75.24) (p < .001). The discrepancies between the instrument's scores were clinically important as the use of only one of the two instruments could result in misclassification of child intellectual ability. These results should prompt professionals working with this clinical population to be cautious when using results from a single instrument in a child's intellectual evaluation.

Intellectual Profiles of Clinic-Referred Preschoolers.

Intellectual impairments in preschoolers have been widely studied. A regularity that emerges is that children's intellectual impairments have an important impact on later adjustments in life. However, few studies have looked at the intellectual profiles of young psychiatric outpatients. This study aimed to describe the intelligence profile of preschoolers referred to psychiatry for various cognitive and behavioral problems in terms of verbal, nonverbal, and full-scale IQ and to examine their association with diagnoses. Three hundred four clinical records from young children aged under 7 years and 3 months who consulted at an outpatient psychiatric clinic and who had one intellectual assessment with a Wechsler Preschool and Primary Scale of Intelligence were reviewed. Verbal IQ (VIQ), Nonverbal IQ (NVIQ), and Full-scale IQ (FSIQ) were extracted. Hierarchical cluster analysis using Ward's method was employed to organize data into groups. The children had, on average, a FSIQ of 81, which is significantly lower than that expected in the general population. Four clusters were identified by the hierarchical clusters analysis. Three were characterized by low, average, and high intellectual ability. The last cluster was characterized by a verbal deficit. Findings also revealed that children's diagnoses were not related to any specific cluster, except for children with an intellectual disability with, as expected, low abilities. Children referred to an intellectual assessment in an early childhood mental health clinic showed an altered intellectual development, more specifically in the verbal domain.