The Utility of the WISC-III Freedom from Distractibility in the Diagnosis of Youth with Attention Deficit Hyperactivity Disorder in a Psychiatric Sample

The “Freedom from Distractibility” (FD) or the Third Factor of the Wechsler Intelligence Scales for Children—Revised (WISC-R), has been used to discern attention deficit hyperactivity disorder (ADHD) from other childhood disorders. This study expands the current research by examining the utility of the Third Factor of the Wechsler Intelligence Scales for Children-III (WISC-III) to differentiate between youth with and without ADHD who are hospitalized at an acute-care psychiatric hospital. There were no significant differences between subjects with and without ADHD on the Third Factor solutions of the WISC-III. The WISC-III FD was not a valid discriminator of psychiatric disorder (affective versus disruptive disorders) or ADHD diagnosis. While these findings question the utility of the Third Factor in the diagnosis of ADHD, the WISC-III FD may be, as described by Kaufman (1994) “a land mine that explodes on a diversity of abnormal populations” (p. 213).