Date of Award
Doctor of Philosophy (PhD)
ADHD comorbidity with other disorders is high in the adult population (over 44% of individuals carry a second diagnosis, 25% anxiety, 18.6% in depression). Separately, these disorders can impact scores on neuropsychological assessments. Little research has investigated how comorbidity among ADHD and other disorders impacts test scores collectively. Given high rates of comorbidity between ADHD and anxiety/depressive disorders and the potential impact on neuropsychological functioning, the current study examined how these comorbid disorders collectively impact cognition. Specifically, the present study investigated differences in full scale intelligence, general ability, and cognitive proficiency on the WAIS-IV between those diagnosed with ADHD only and those who also have a comorbid anxiety/depressive disorder. This study also investigated the impact of these comorbid diagnoses on working memory, processing speed, executive functioning, and inattention/impulsivity. Specifically, this study tested whether the relationship between ADHD and these four outcome variables could be predicted by the presence of a comorbid anxiety/depressive disorder. Results indicated that there were no significant differences between the two groups for full scale intelligence or general ability. Across both groups, participants had lower cognitive processing scores when compared to general ability scores. With regards to the predictive ability of a comorbid diagnosis, only two of the analyses were significant. The presence of an anxiety or depressive disorder predicted the relationship between ADHD and working memory and a measure of visual scanning, sequencing, and psychomotor speed (Trailmaking A). In other words, scores on these two outcome variables differentiated participants who had a co-occurring anxiety or depression diagnosis from those with only ADHD. This study addresses a gap that exists in the current literature by focusing on ADHD comorbid with other disorders, a highly common occurrence that has been infrequently studied. This study also investigates these disorders in an adult population, contrasting previous research that focused solely on children and adolescent populations.
Bain, Cristina V..
"Attention Deficit Hyperactivity Disorder with Comorbid Anxiety/Depression in Adults: Impacts on Neuropsychological Functioning"
(2018). Doctor of Philosophy (PhD), dissertation, Psychology, Old Dominion University, DOI: 10.25777/knew-5m73