The Interaction of ADHD-Traits and Trait Anxiety on Inhibitory Control

ADHD and anxiety frequently occur together; however, the cognitive outcomes of co-morbid anxiety and ADHD are not straightforward. A potential explanation for conflicting results in the literature may be that different core ADHD symptoms show different interactions with anxiety depending on the task processing demands. To address this question, we investigated whether different ADHD traits are related to different inhibitory outcomes, contingent upon the level of trait anxiety. The sample consists of 60 non-clinical university students (X ̅age= 20.5, 53% male). Conners’ Adult ADHD Rating Scale (CAARS-SL) and State Trait Anxiety Inventory (STAI) were used to measure ADHD-traits and anxiety, respectively. The participants completed a visual Go/NoGo task with and without distractor conditions while continuous EEG was recorded. Inhibitory control was operationalized as the frontocentral N2 maximum peak amplitude elicited in response inhibition (NoGo/No Distractor), cognitive inhibition (Go/Distractor), dual inhibition (NoGo/Distractor), and control (Go/No Distractor) conditions. We analyzed the moderating effect of trait anxiety on the prediction of inhibitory control by ADHD scores for each Go/NoGo condition with the varying inhibition demands. Results showed that trait anxiety moderated the effects of total ADHD and hyperactivity-impulsivity scores, but only in the response inhibition condition (NoGo/No Distractor). Additionally, inattentiveness was related to attenuated N2 amplitudes in the cognitive inhibition condition (Go/Distractor). These findings suggest that depending on the inhibitory demands of the task, unique cognitive outcomes may occur when different ADHD traits coexist with anxiety.