Abstract
<b><i>Background:</i></b> This review unpacks the emotional presentation of externalizing behaviors in attention deficit hyperactivity disorder (ADHD), by diving into the psychophysiology, neurophysiology, and neurogenetics in relation to executive function. The correlations among these three variables are identified, showing that standard assessments for ADHD leave out the emotional dysregulation element. This may lead to suboptimal management outcomes during the developmental progression into adolescence and adulthood. <b><i>Summary:</i></b> The emotional impulsivity manifestation in adolescence and adulthood related to the under-managed emotional dysregulation in childhood is found to be associated with subtle confounding impact of 5-HTTLPR (serotonin-transporter-linked promoter region) genotype. The genotype of interest affects the neurochemistry, neurophysiology, and psychophysiology of the cognition for executive function. The established practice of using methylphenidate in treating ADHD surprisingly has a neurogenetic effect in targeting the genotype of interest. Methylphenidate provides neuroprotective effects throughout the neurodevelopment timeline from childhood to adulthood. <b><i>Key Messages:</i></b> The emotional dysregulation element in ADHD which is often overlooked should be addressed to improve the prognostic outcomes in adolescence and adulthood.