Differences in executive functioning between adults with ADHD and those diagnosed with other psychiatric diagnoses: Utility of the CTMT and the WAIS-IV.

In this study, the utility of the Comprehensive Trail Making Test (CTMT) and WAIS-IV working memory (WMI) and processing speed (PSI) indices in assessment of ADHD were examined. Using retrospective analysis of data from two private practices, patients were classified as having ADHD, having another psychiatric disorder, or having comorbid ADHD and other psychiatric disorder. Results indicated that significant differences existed in performance across the three groups [F(6, 246) = 3.38, p = .003; Pillai's Trace = 0.152, partial η² = 0.076] on CTMT scores (p < .05), WMI scores (p ≤ .001) and PSI scores (p < .05). Logistic regression analyses indicated WMI and CTMT trail 5 scores were individually useful indicators in identifying the presence of ADHD. Analysis also indicated minimal increase in correct classification of presence or absence of ADHD through combining CTMT, WMI, and PSI scores. Clinical implications for neuropsychological assessment and differential diagnosis of ADHD are discussed.