Attention Deficit Hyperactivity Disorder

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by persistent symptoms of inattention, hyperactivity, and impulsivity that interfere with functioning or development. It commonly manifests in childhood and can continue into adulthood, affecting attention span, organization, task completion, and impulse control. Symptoms include difficulty sustaining focus, making careless mistakes, avoiding mentally demanding tasks, fidgeting, restlessness, excessive talking, interrupting others, and acting without considering consequences. ADHD is categorized into three subtypes: Predominantly Inattentive Type, Predominantly Hyperactive-Impulsive Type, and Combined Type. Genetic factors play a significant role, with evidence of altered brain structure and function, particularly in regions related to executive function such as the prefrontal cortex. The DRD4 gene is associated with ADHD, and pathways involving dopamine signaling and neurotransmitter regulation are implicated. Treatments may include medications like methylphenidate and behavioral interventions, with some drugs such as ziprasidone and topiramate being explored in clinical contexts. ADHD is also linked to other conditions such as autism spectrum disorder and Tourette syndrome.