• ADHD
• cognitive flexibility
• emotional dysregulation
• Emotional Picture Sorting Task
• executive control
• executive functions
• Wisconsin Card Sorting Task

Abstract
Background: ADHD often persists into adulthood and frequently co-occurs with
emotional dysregulation (ED), a transdiagnostic trait associated with greater impair-
ment. It is plausible that ED in the context of ADHD may arise from mechanisms dis-
tinct from those underlying ED alone. Although the emotional dimension of adult
ADHD is acknowledged, its neuropsychological characterization—particularly
when executive control is challenged by emotionally salient stimuli—remains in-
complete. Comparing cognitive control over neutral and emotionally salient stimuli
across ADHD, ED, ADHD+ED and healthy controls (HC) may help disentangle
shared and specific processes, paving the way for more tailored, precision-based
diagnostic and therapeutic approaches.
Materials and Methods: 101 adult participants (18 years) were recruited at
the Psychiatry Unit of Pisa University Hospital (Italy), including 23 individuals
with ADHD, 27 with ADHD+ED, 28 with ED, and 23 HC. Executive functioning
was assessed using a computerized version of the Wisconsin Card Sorting Task
(WCST) and its emotional analogue, the Emotional Picture Sorting Task (EPST),
implemented on PEBL. Both tasks required rule inference and set-shifting, but only
EPST used task-relevant affectively salient stimuli. Eleven performance variables
reflecting overall performance, sustained attention and cognitive flexibility were
extracted and analyzed. Group (between-subject) and task (within-subject) effects
were tested using mixed ANOVA.
Results: Clinical groups had a worse overall performance than HC based on the
number of trials required to complete the tasks. A trend toward a higher number of
failures to maintain set was observed in ADHD groups compared to HC, reflecting a
greater impairment in sustained attention, independently from the task. Compared
to the WCST, the EPST was characterized by an increased rate of unique errors
and failures to maintain set across groups, implying greater difficulty, possibly
due to the need to engage emotion recognition abilities. While more pronounced
impairments in cognitive flexibility (i.e., perseverative responses and errors) on
the WCST were found in participants with ADHD+ED and ED compared to HC, a
group-specific improvement in conceptual level responses, perseverative responses
and errors was observed in the ED group on the EPST, i.e., when emotional stimuli
were used.
Discussion: These findings strengthen the hypothesis of at least partially differ-
ent mechanisms underlying ED in ADHD vs. non-ADHD individuals, suggesting
increased sensitivity to emotionally salient stimuli in people with ED without
ADHD leading to improved performance when emotion recognition is required to
complete a task. From a theoretical standpoint, this notion could lead to a better
understanding of emotional processing and emotion regulation across diagnoses,
while providing clinicians with new tools to better assess ED symptoms within a
patient-tailored framework. However, based on our data, it cannot be excluded
that ED may be subtended by increased sensitivity to emotional stimuli both in
people with and without ADHD, with the presence of ADHD hindering its adaptive
potential.
Conclusions: This study provided preliminary evidence on ED neuropsycho-
logical correlates in ADHD vs. non-ADHD individuals. Further study in wider
samples, with greater statistical power, could allow to further explore neuropsy-
chological nuances regarding the valence and task-relevance of emotional stimuli,
to control for learning effects and to characterize subgroups of ED. Longitudinal
studies are also warranted to assess treatment response in relation to different
neuropsychological phenotypes