Chapter 8: Attention-Deficit/Hyperactivity Disorder (ADHD)

The diagnostic framework presented in the DSM-5-TR recognizes three distinct presentations: the predominantly inattentive type emphasizing attention deficits and organizational difficulties, the predominantly hyperactive-impulsive type marked by restlessness and hasty actions, and the combined type displaying both symptom clusters equally. Diagnosis requires evidence of symptom onset before age twelve, consistency across multiple environments such as home and school, and developmental inappropriateness relative to peer functioning. The neurobiological basis of ADHD centers on dysregulation of dopaminergic and noradrenergic neurotransmitter systems that modulate executive functioning and behavioral inhibition. Neuroimaging research documents structural and functional alterations in the prefrontal cortex, which governs planning and impulse control, alongside abnormalities in the basal ganglia and disrupted connectivity within the default mode network. Beyond primary attention and behavioral symptoms, ADHD frequently co-occurs with learning disorders, emotional dysregulation, and social competence deficits. Common comorbid conditions include oppositional defiant disorder, conduct disorder, anxiety disorders, and mood disturbances, which compound functional impairment and treatment complexity. The developmental trajectory of ADHD often extends into adolescence and adulthood, with symptoms adapting to changing environmental demands. Treatment approaches integrate pharmacological and behavioral components, particularly stimulant medications such as methylphenidate and amphetamine formulations that enhance catecholamine availability, alongside behavioral parent training that strengthens contingency management and family functioning, classroom-based accommodations and behavioral strategies, and comprehensive psychosocial interventions. Research demonstrates that multimodal treatment combining medication with behavioral therapy produces superior outcomes compared to either intervention alone, highlighting the importance of individualized, coordinated treatment planning across clinical and educational settings.