A-168 The Role of Executive Functioning, Processing Speed, and Working Memory on the TMT-B in ADHD Populations

Abstract

Abstract Objective: Trail-Making Test B (TMT-B) is a measure of attention and processing speed (PS), with sensitivity to executive functioning (EF; Reimers, 2019). The impacts of these domains on TMT-B are not well-understood, especially in those with Attention-Deficit/Hyperactivity Disorder, who experience deficits in EF, PS, and attention (Kramer et al., 2020, Theiling & Petermann, 2016). We examined the contributions of EF, PS, and attention on TMT-B performance. Method: This study included archival data of 64 adults diagnosed with ADHD at a midwestern multidisciplinary behavioral health clinic. Commonality analyses were used to identify the predictive capacity of performance on measures of EF, attention, and PS on TMT-B. EF was measured using perseverative errors of Wisconsin Card Sort Test (WCST). Weschler Adult Intelligence Scale (WAIS) index scores of working memory (WMI), and processing speed (PSI) were used to examine attention and PS. Results: Data was analyzed using a series of block-wise hierarchical regression analyses, with each predictor variable entered in alternating sequence. Results indicated that the processing speed domain accounted for 10.8% (R2 change = .108, F(1, 60) = 8.407, p < .01) of the variance in TMT-B performance after controlling for variability accounted for by other domains. EF was a significant predictor after accounting for variability in other domains, but accounted for only 5% (R2 change = .05, F(1, 60) = 4.179, p < .045) of the variance. WMI was not a significant predictor in this clinical sample. Conclusion: TMT-B is affected by both PS and EF. Implications and limitations of this study will be discussed.