The WISC-III Freedom from Distractibility factor: Its utility in identifying children with attention deficit hyperactivity disorder.

Factor analytic studies of the Wechsler Intelligence Scale for Children—Revised (WISC–R; Wechsler, 1974) have consistently identified what is commonly known as the Freedom From Distractibility (FFD) factor, consisting of the Arithmetic, Digit Span, and Coding subtests (Kaufman, 1979). Support for the validity of this factor stems in part from studies that found significant correlations between the WISC–R FFD subtests and other established measures of attention, such as Continuous Performance Tests (Klee & Garfinkel, 1983) and teacher ratings (Reschly & Reschly, 1979). Additional support comes from investigations that detected significantly lower FFD scores among groups of children with attention deficit hyperactivity disorder (ADHD; American Psychiatric Association, 1987) in comparison with control children (Lufi, Cohen, & Parish-Plass, 1990).