Overview
Definition
A neurodevelopmental disorder characterized by persistent, developmentally inappropriate levels of inattention, hyperactivity, and impulsivity that impair functioning.
Epidemiology
Affects 5-9% of school-aged children. More commonly diagnosed in boys (inattentive type often missed in girls). Persists into adulthood in ~50% of cases.
Etiology & Risk Factors
- Genetic factors (heritability >70%)
- Dopaminergic and noradrenergic pathway dysregulation in the prefrontal cortex
Clinical Symptoms
- Inattention: Difficulty sustaining attention, forgetfulness, losing items, easily distracted, poor organization
- Hyperactivity/Impulsivity: Fidgeting, inability to remain seated, running/climbing inappropriately, talking excessively, interrupting, blurting out answers
- Symptoms must be present before age 12, occur in >= 2 settings (school, home), and interfere with functioning
Clinical Approach
Diagnosis
- DSM-5 criteria requiring at least 6 symptoms of inattention and/or hyperactivity-impulsivity (5 for adolescents/adults)
- Rating scales from parents and teachers (e.g., Vanderbilt scales)
Management
- Pharmacotherapy: Stimulants (Methylphenidate, Amphetamine compounds) as first-line
- Non-stimulants: Atomoxetine, alpha-2 agonists (Guanfacine, Clonidine)
- Behavioral therapy (parent training, classroom modifications)
- Combined behavioral and pharmacological therapy (most effective)
Complications
- Academic failure
- Social rejection / Relationship difficulties
- Increased risk of substance abuse and accidents in adolescence/adulthood