Child & Adolescent Psychiatry (ADHD, Autism, Conduct)
A boards-focused tour of child & adolescent psychiatry: DSM-5 criteria with exact durations/onset, epidemiology, buzzword vignettes, and first-line management for ADHD, autism spectrum disorder, ODD, and conduct disorder — built around the next-best-step decisions examiners test.
How the boards test child psychiatry
Child & adolescent psychiatry on the exam centers on two heavily tested clusters: neurodevelopmental disorders (ADHD, autism spectrum disorder) and the disruptive, impulse-control & conduct disorders (oppositional defiant disorder, conduct disorder). Vignettes reward two skills: (1) matching a behavioral pattern to the correct DSM-5 label using duration, onset, and setting criteria, and (2) choosing the next best step, which is usually a specific therapy or a first-line drug rather than more testing.
Three discriminators come up again and again: age of symptom onset (several ADHD symptoms before age 12; ASD in the early developmental period), number of settings (ADHD requires ≥2, e.g., home and school), and whether the behavior violates the rights of others — the single line that separates ODD from conduct disorder. Comorbidity is the rule: ADHD frequently coexists with ODD, learning disorders, and anxiety, so a vignette may bait you toward the wrong primary diagnosis.
- DSM-5: ≥6 symptoms of inattention and/or hyperactivity-impulsivity (≥5 if age ≥17) for ≥6 months, present in ≥2 settings, with several symptoms before age 12, causing functional impairment
- Three presentations: inattentive, hyperactive-impulsive, combined
- Epidemiology: ~5-11% of children; boys > girls (~2:1); ~50% carry symptoms into adulthood
- Buzzwords: careless mistakes, loses homework, can't wait turn, blurts out answers, fidgets, "on the go as if driven by a motor"
- First-line, age ≥6: stimulant (methylphenidate or an amphetamine) plus behavioral therapy
- Preschool (age 4-5): parent behavior management training FIRST; add methylphenidate only if inadequate
- Non-stimulants: atomoxetine (NRI) and alpha-2 agonists (guanfacine/clonidine) — favored with tics, anxiety, or stimulant intolerance
- Stimulant AEs: ↓appetite, weight loss/growth suppression, insomnia, ↑HR/BP — screen cardiac history, monitor height/weight
Stem: A 5-year-old boy is evaluated for constant fidgeting, interrupting, and inability to stay seated. His teacher and parents both report the behavior daily for 8 months. Development is otherwise normal; hearing and vision are intact.
Diagnosis: ADHD, combined presentation — symptoms in ≥2 settings, >6 months, onset before age 12, impairing function.
Next best step: Because he is age 4-5, start parent-focused behavior management training first — not a stimulant. Methylphenidate is added only if behavioral therapy is insufficient.
Contrast: The identical picture in an 8-year-old → first-line is a stimulant (methylphenidate) plus behavioral therapy. Recognizing the age cutoff is the whole point of the question.
- Two core domains, BOTH required: (1) persistent deficits in social communication/interaction; (2) restricted, repetitive patterns of behavior/interests
- Domain-2 features: insistence on sameness/routines, stereotypies (hand-flapping, lining up toys), fixated interests, sensory hyper-/hyporeactivity
- Onset in the early developmental period; DSM-5 merged Asperger, PDD-NOS, childhood disintegrative disorder into one spectrum with severity levels 1-3 (support needed)
- Buzzwords: no eye contact, echolalia, delayed/absent language, doesn't point to share interest, upset by change in routine
- Epidemiology: ~1 in 31 children (CDC 2022 data; up from 1 in 36); boys > girls (~3-4:1); IQ varies (subset with intellectual disability)
- Risk factors: advanced parental age, in-utero valproate, prematurity — NOT vaccines/MMR (debunked)
- Management: early intensive behavioral intervention / ABA, speech & occupational therapy (no cure)
- Risperidone or aripiprazole: only FDA-approved meds — for irritability/aggression associated with ASD
Side-by-side: criteria, timeframes, drugs
| Disorder | Hallmark | Duration / onset | First-line management |
|---|---|---|---|
| ADHD | Inattention &/or hyperactivity-impulsivity; ≥6 sx, ≥2 settings | ≥6 mo; several sx before age 12 | Age ≥6: stimulant + behavior therapy; age 4-5: parent training first |
| ASD | Social-communication deficits + restricted/repetitive behavior | Early developmental period | ABA/speech/OT; risperidone/aripiprazole for irritability |
| ODD | Angry/irritable, argumentative/defiant, vindictive; rights NOT violated | ≥4 sx, ≥6 months | Parent management training |
| Conduct | Violates others' rights: aggression to people/animals, property destruction, theft/deceit, rule violations | ≥3 sx in 12 mo, ≥1 in 6 mo; age <18 | Multisystemic therapy / parent training; treat comorbidities |
| DMDD | Severe recurrent temper outbursts + chronic irritable mood | ≥12 mo; onset <10, dx ages 6-18 | CBT / parent training; treat mood |
Stem: A 14-year-old boy has a 1-year history of bullying peers, torturing the family cat, shoplifting, and setting a fire in an abandoned lot; he has run away overnight twice.
Diagnosis: Conduct disorder — a pattern violating others' rights/animals, ≥3 behaviors over 12 months, age <18.
Next best step: evidence-based psychotherapy — multisystemic therapy or parent management training. There is no FDA-approved drug for conduct disorder, so treat comorbid ADHD/depression.
Board traps:
- Only arguing, defying rules, losing temper, blaming others WITHOUT violating rights → ODD, not conduct disorder.
- Same traits at age ≥18 plus conduct disorder before 15 → antisocial personality disorder.
The timeframes are pure points — anchor them:
- ADHD = "6-6-2-before-12": ≥6 symptoms, ≥6 months, ≥2 settings, onset before age 12
- ODD = ≥4 symptoms, 6 months, rights intact
- Conduct = "3 in 12, 1 in 6": ≥3 criteria in 12 months, ≥1 in the last 6 months
- DMDD = "<10 & 12": onset before age 10, outbursts ≥12 months (diagnosed ages 6-18)
- ASD = early developmental period (no fixed month count)
Rights test: violates others' rights / hurts animals → conduct; merely defiant and angry → ODD.
- Before a stimulant: take a cardiac history and family history of sudden death; routine ECG is NOT required without cardiac red flags (AAP)
- Stimulant intolerance, tics, or comorbid anxiety → switch to atomoxetine or an alpha-2 agonist (guanfacine/clonidine)
- Atomoxetine and SSRIs carry a black-box warning for suicidal ideation in youth — monitor closely
- Monitor height/weight on stimulants (growth suppression); appetite loss and insomnia are common
- ODD / conduct disorder: the tested answer is almost always a behavioral/psychotherapy intervention (parent management training, multisystemic therapy), not a drug
- ASD irritability/aggression: risperidone or aripiprazole are the only FDA-approved options
- Comorbidity rule: treat the ADHD even when it coexists with ODD/conduct — controlling ADHD often improves the disruptive behavior
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