Abstract
Compared factor analyses of teacher ratings of attention-deficit hyperactivity disorder (ADHD) and oppositional defiant disorder(ODD) symptoms in Puerto Rican children, aged 4 and 5 (n = 665) and 6 through 13 years (n = 680), referred or identified as in need of referral for psychoeducational services. Factor analyses of the 4- and 5-year-old sample yielded Attention-Deficit-Hyperactivity and Oppositional Defiant factors that encompass all but one of the ADHD and ODD symptoms, respectively. Factor analyses for children aged 6 through 13 years yielded Hyperactivity-Impulsivity, Inattention-Distractibility and Oppositional Defiant factors. Factor structures obtained for boys and girls were similar at both age groups. Findings suggest that a unidimensional conceptualization of teacher ratings of ADHD, as implied in the Diagnostic and Statistic Manual of Mental Disorders (3rd ed., rev.; DSM-III-R; American Psychiatric Association, 1987) is appropriate for preschool children but not for children aged 6 through 13 years. A bidimensional (hyperactivity and inattention) conceptualization of ADHD for the latter age group seems appropriate. Finally, a unidimensional conceptualization of ODD seems appropriate for both samples. The conceptual and clinical implications of these findings for the nosology of ADHD are discussed.