Attention-Deficit/Hyperactivity Disorder

ADHD Overview - Defining the Buzz

• Definition: ADHD is a neurodevelopmental disorder characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity that significantly impacts functioning or development across multiple settings.
• Core Symptom Clusters:
  • Inattention: Difficulty sustaining focus, disorganization.
  • Hyperactivity: Excessive motor activity, restlessness.
  • Impulsivity: Hasty actions, difficulty waiting turns.
• Epidemiology:
  • Prevalence: Affects ~5-7% of school-aged children globally; Indian data suggests similar rates.
  • Male:Female Ratio: Typically 2:1 to 4:1 in clinical settings.

⭐ Symptoms must be present before age 12 for diagnosis.

ADHD Etiology - Brain's Busy Signals

• Neurobiology: Core imbalance involves neurotransmitters.
  • Key players: Dopamine (DA) & Norepinephrine (NE) dysregulation.
  • Brain structures implicated:
    • Prefrontal Cortex (executive function).
    • Basal Ganglia (reward, motivation).
    • Cerebellum (timing, coordination).
  • 
• Genetics: Strong genetic predisposition.
  • High heritability: Estimated at 70-80%.
  • Associated genes: $DRD4$ (dopamine receptor D4), $DAT1$ (dopamine transporter).

  • ⭐ ADHD is one of the most heritable psychiatric disorders.

• Environmental Risk Factors: Contribute to vulnerability.
  • Prenatal: Maternal smoking, alcohol use during pregnancy.
  • Perinatal: Prematurity, low birth weight (LBW).
  • Postnatal: Exposure to toxins like lead.

ADHD Diagnosis - Spotting the Symptoms

• Core DSM-5 Criteria:

  • Symptom Duration: ≥6 months.
  • Onset: Several symptoms present before age 12.
  • Impairment: Clinically significant, in ≥2 settings (e.g., home, school/work).

  ⭐ For ADHD diagnosis, symptoms must cause impairment in at least two settings.

• Symptom Thresholds (DSM-5):

  • Inattention: ≥6/9 symptoms for children (e.g., easily distracted, trouble organizing). For adolescents/adults (age 17+): ≥5/17 symptoms.
  • Hyperactivity/Impulsivity: ≥6/9 symptoms for children (e.g., fidgets, often interrupts). For adolescents/adults (age 17+): ≥5/17 symptoms.
    • 📌 Mnemonic hint: 'CAN I SIT STILL' (hyperactivity/impulsivity).

• Presentations (Subtypes):

  • Predominantly Inattentive Presentation.
  • Predominantly Hyperactive/Impulsive Presentation.
  • Combined Presentation.

• Common Comorbidities:

  • Oppositional Defiant Disorder (ODD) (~50%).
  • Conduct Disorder (CD), Anxiety Disorders.
  • Learning Disorders, Mood Disorders, Tic disorders.

• Differential Diagnosis:

  • Normal active child, situational anxiety.
  • Depression, other mental health conditions.
  • Learning Disorders (LD), Intellectual Disability.
  • Sensory processing issues, Thyroid disorders, sleep disorders.

ADHD Management - Taming the Tornado

• Core Principle: Multimodal approach (pharmacotherapy + behavioral therapy) is superior for optimal outcomes.

• Pharmacotherapy:

  • First-line: Stimulants
    • Methylphenidate (MPH): Start 5mg BD/TDS. Max: 60mg/day or 2mg/kg/day.
    • Amphetamines (e.g., Dextroamphetamine).
    • Common Side Effects: Insomnia, ↓appetite, weight loss, headache, abdominal pain, tics.
  • Second-line/Adjuncts: Non-stimulants
    • Atomoxetine (ATX): Start 0.5mg/kg/day, target 1.2mg/kg/day. Max: 100mg/day or 1.4mg/kg/day.
    • Side Effects: GI upset, sedation, ↓appetite, dizziness, ↑HR/BP. ⚠️ Monitor for suicidal ideation (rare).
    • Alpha-2 Agonists: Clonidine, Guanfacine (especially for tics, aggression, sleep issues).

• Behavioral Interventions:

  • Parent Management Training (PMT): For parents of children <12 years.
  • Behavioral Classroom Management: Teacher-led strategies.
  • Social Skills Training.
  • Cognitive Behavioral Therapy (CBT): For adolescents/adults, addresses co-occurring issues.

• Monitoring: Regular checks for efficacy, side effects, growth (height, weight), BP, HR.

⭐ Methylphenidate is the most commonly prescribed first-line medication for ADHD.

High‑Yield Points - ⚡ Biggest Takeaways

• Core features: Persistent inattention, hyperactivity, and impulsivity; symptoms present before age 12.
• Diagnosis requires impairment in ≥2 settings (e.g., home, school/work).
• Most prevalent neurodevelopmental disorder of childhood, often persisting.
• First-line pharmacotherapy: Stimulants (e.g., methylphenidate, amphetamines) are most effective.
• Alternative medications: Non-stimulants like atomoxetine, guanfacine, or clonidine.
• Frequently associated with comorbidities: ODD, conduct disorder, anxiety, and learning disabilities.
• Symptoms may persist into adulthood, though hyperactivity often lessens an_d inattention may predominate_