The Tower of London(DX): a standardized approach to assessing executive functioning in children.

In the current study, the Tower of London (Shallice, 1982) was modified to enhance its clinical utility as a measure of childhood executive functioning. The Tower of London-Drexel (TOL(DX)) was administered to normal control (NC; N = 56) and attention-deficit hyperactivity disorder (ADHD; N = 99) children (ages 7 to 12) to determine whether age-related changes in performance were evident, to gather normative data, and to evaluate the test-retest reliability and criterion-validity of the measure. The results revealed age-related changes in score performance, age-group normative data, an acceptable level of reliability and significant differences in performance of NC and ADHD subjects. Further, discriminant analysis classification rates determined that the TOL(DX) was sensitive and highly specific to ADHD. Implications and limitations of the study are discussed.