• ADHD
• Anxiety disorders
• Autism spectrum disorders
• Emotional dysregulation
• Inattention
• Mood disorders
• Neurodevelopmental disorder
• Psychiatric comorbidity

Abstract

Background: The association between emotional dysregulation (ED) and attention-deficit/hyperactivity disorder (ADHD) has been widely studied and supported in literature. However, a consensus has yet to be reached on how to conceptualize this clinically challenging domain within ADHD. Particularly, the association between ADHD and ED may represent a distinct condition, a more severe form of ADHD, or a specifier related to the occurrence of other comorbid disorders. In our study, we explored these three main hypotheses investigating clinical differences between patients with ADHD, ADHD+ED and ED alone.
Methods: A total of 101 participants (ages 18-50) were divided into four groups: ADHD, ED, ADHD+ED and healthy controls (HC). In a single interview, age, sex, educational history, marital status and clinical anamnestic data were recorded. Psychiatric conditions were assessed according to DSM-5 criteria. ADHD diagnostic criteria and ADHD and ED symptom severity were assessed, respectively, using the Diagnostic Interview for ADHD in adults (DIVA-5) and the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS). Additional information on symptom severity was gathered through informant- and self-reported scales.
Results: ADHD and ADHD+ED participants shared a significantly lower educational level and significantly more severe inattention, and hyperactivity/impulsivity symptoms compared to HC. ADHD symptoms severity was intermediate in participants with ED, who generally showed greater inattention, but similar hyperactivity compared to HC. No differences in ADHD severity were found between ADHD groups, except for more severe informant-reported inattentive and accessory symptoms in ADHD+ED vs. ADHD. As for psychiatric comorbidities, ADHD+ED participants had the highest number of neurodevelopmental and psychiatric conditions. While sharing with ED participants significantly higher rates of mood disorders and anxiety disorders compared to ADHD, they specifically presented with the highest rates of neurodevelopmental disorders, particularly autism spectrum disorders, and disruptive disorders. Additionally, in those with depressive disorders, ADHD+ED was associated with a lower age at first episode compared to both ADHD and ED and with increased cyclicity compared to ADHD.
Conclusion: These findings suggest that ADHD with ED is unlikely to represent merely a more severe form of ADHD but may be better conceptualized as an indicator of affective comorbidity. Nevertheless, comparisons with participants with ED without ADHD highlighted specific clinical features, including a higher neurodevelopmental load, more impulse-control disorders and a poorer course of mood disorders. Accordingly, rather than an additive effect of ED in ADHD, our results support an interaction between these two conditions, contributing to the definition of a distinct subtype of ADHD and mood disorders characterized by a greater clinical complexity.