Date of Graduation


Document Type


Degree Type



College of Education and Human Services


Counseling, Rehabilitation Counseling & Counseling Psychology

Committee Chair

Monica Leppma

Committee Member

James Bartee

Committee Member

Jeff Daniels

Committee Member

Daniel Long

Committee Member

Christine Schimmel


Attention-Deficit/Hyperactivity Disorder (ADHD) ranks among the most common mental health disorders in adults (APA, 2013). ADHD assessment is complicated by heterogenous symptoms, gender and age differences in diagnosis, variability in symptom manifestation across the lifespan, and comorbidity with other psychiatric disorders and medical conditions (Asherson, 2016; Willcut, 2012; Williamson & Johnston, 2015). The stop-signal task (SST) identifies ADHD clinical groups in children and adults (Lifffijt et al., 2005), yet it remains unclear whether SST performance reflects general deficits in attention (Alderson et al., 2007) or a selective deficit in motor response inhibition (Aron & Poldrack, 2005). Studies of SST often involve lower cognitive complexity without the additional inhibitory load produced by interference control (Uno et al., 2006). Currently, there is no research on SST with interference control in the adult population. The aim of this study was to assess the diagnostic utility of response inhibition metrics in the adult population on tasks with greater central processing demands. Forty-nine adults completed the Adult ADHD Self-Report Scale – V1.1 Symptoms Checklist and the Test of Differential Inhibition and Attention (TDIA). Results from hierarchical multiple linear regression analyses showed that TDIA metrics associated with motor response inhibition significantly predicted self-reported symptoms of inattention, hyperactivity-impulsivity, and combined ADHD, over and above metrics representing general attention. This study supports the clinical utility of SST with interference control in identifying ADHD in adults. Furthermore, the results support a conceptual model of ADHD wherein response control deficits are primary to the executive dysfunction associated with the disorder. Possible explanations for these results, limitations of the study, and future directions are explored.


Should the title of the uploaded file match the title of the manuscript? It is fine this way/DB