U01.13.009 Childhood and early-onset disorders

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Learning Objectives

Master the Childhood and Early-Onset Psychiatric Disorders. Distinguish between externalizing behavioral disorders (Conduct, ODD) and neurodevelopmental conditions (ADHD, ASD), focusing on diagnostic age cutoffs and high-yield comorbidities for the USMLE Step 1.

1. Neurodevelopmental & Cognitive Disorders

These disorders involve impairments in the growth and development of the brain or central nervous system, often affecting learning and social interaction.

Disorder Diagnostic Hallmarks & Details Management
ADHD Onset before age 12 (dx after age 4). Inattention, hyperactivity, or impulsivity in ≥ 2 settings. Often persists into adulthood. Stimulants (Methylphenidate); Alt: Atomoxetine, \alpha_2-agonists.
Autism (ASD) Social/communication deficits; repetitive behaviors. Associated with increased head/brain size. More common in males. Behavioral therapy: specialized support.
Intellectual Disability Global cognitive/adaptive deficits affecting reasoning, memory, and independence. Special education, occupational therapy.
Specific Learning Disorder Deficit in a specific subject (reading, math) for ≥ 6 months. Normal intelligence/IQ. Academic support and counseling.

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2. Behavioral & Impulse-Control Disorders

These conditions involve patterns of aggression or defiance that disrupt social norms and violate the rights of others.

Disorder Clinical Presentation High-Yield Distinction
Conduct Disorder Violates societal norms (theft, aggression, property destruction). Becomes Antisocial Personality Disorder after age 18.
Oppositional Defiant (ODD) Defiance, irritability, and vindictiveness toward authority for ≥ 6 months. No physical aggression or violation of basic rights.
Intermittent Explosive Recurrent verbal/physical outbursts < 30 mins. Not premeditated. Associated with an immediate sense of relief followed by remorse.
Disruptive Mood Dysregulation Onset before age 10. Constant anger/irritability between outbursts. Outbursts are out of proportion to the situation.

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3. Anxiety, Tic, & Communication Disorders

These disorders focus on specific developmental anxieties, motor/vocal tics, or situational speech limitations.

Disorder Diagnostic Characteristics Timeline & Comorbidities
Tourette Syndrome Both multiple motor AND ≥ 1 vocal tic. Grimacing, grunting, coprolalia. Onset < 18; persists > 1 year. High association with OCD and ADHD.
Separation Anxiety Fear of separation from attachment figures. May feign illness to avoid school. Lasts ≥ 4 weeks. (Normal up to age 3–4).
Selective Mutism Refusal to speak in specific situations (e.g., school) despite speaking elsewhere. Lasts ≥ 1 month. (Onset < 5). Often coexists with Social Anxiety.

 

 

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High-Yield Clinical Pearls:

  • ADHD Rule: Diagnosis requires symptoms in two or more settings. If symptoms only occur at school, investigate a learning disorder.
  • Conduct vs. ODD: Remember “Conduct = Criminal” (hurting animals, theft, arson). ODD is just being “defiant” and argumentative.
  • Tourette Management: Use \alpha_2-agonists (Guanfacine) for tics + ADHD; use Tetrabenazine or antipsychotics for severe cases.
  • Intellectual Disability: Requires a global impairment (both IQ and adaptive functioning).

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