Table of Contents
High-yield pediatric + psychiatry notes
Synthesized around Nelson Textbook of Pediatrics, standard child psychiatry concepts/DSM-5, and current AAP guidance. The AAP guideline recommends DSM-5-based diagnosis, assessment across more than one setting, screening for comorbidities, and age-specific treatment. (American Academy of Pediatrics)
1. Definition
ADHD is a neurodevelopmental disorder characterized by a persistent pattern of:
- Inattention
- Hyperactivity
- Impulsivity
that is developmentally inappropriate, persists over time, occurs in ≥2 settings, and causes clinically significant impairment in academic, social, family, or occupational functioning.
It is a chronic disorder, although symptom pattern and functional impact may change with age. (American Academy of Pediatrics)
2. Epidemiology
- One of the most common neurobehavioral disorders of childhood
- Approximately 7–8% of children/youth in commonly cited US epidemiologic estimates. (American Academy of Pediatrics)
- Male predominance, particularly for the hyperactive/impulsive presentation.
- Girls are more likely to present predominantly with inattention, so they may be underrecognized.
- Symptoms frequently continue into adolescence and adulthood.
Typical age of recognition
- Often becomes obvious when academic and behavioral demands increase, particularly after school entry.
- Symptoms may be present much earlier.
- DSM-5 requires several symptoms to have been present before age 12 years.
3. Etiology and Pathophysiology
ADHD is multifactorial.
A. Genetic factors — most important
ADHD has a strong familial/genetic component.
Important neurotransmitter systems:
- Dopamine
- Norepinephrine
- To a lesser extent, serotonergic systems
Important brain circuits:
- Prefrontal cortex
- Basal ganglia/striatum
- Anterior cingulate cortex
- Frontostriatal networks
These circuits are involved in:
- Attention
- Executive function
- Response inhibition
- Working memory
- Motivation/reward processing
B. Environmental/perinatal associations
Associations include:
- Prematurity
- Low birth weight
- Prenatal tobacco exposure
- Prenatal alcohol exposure
- Certain prenatal toxic exposures
- Psychosocial adversity
Important: These are risk factors/associations, not usually sufficient by themselves to establish causation.
C. Not established as primary causes
ADHD is not simply caused by:
- Poor parenting
- Excessive sugar
- Watching television
- Lack of discipline
However, environmental factors can influence severity and functional impairment.
4. Core Clinical Features
Think:
INATTENTION + HYPERACTIVITY + IMPULSIVITY
A. Inattention
Child may:
- Fail to give close attention to details
- Make careless mistakes
- Have difficulty sustaining attention
- Seem not to listen when spoken to
- Fail to follow through on instructions
- Have difficulty organizing tasks
- Avoid tasks requiring sustained mental effort
- Lose things necessary for activities
- Be easily distracted
- Be forgetful in daily activities
Common real-life presentation
- Homework incomplete
- Frequently loses pencils/books
- Starts several tasks but finishes few
- Appears to “daydream”
- Needs repeated instructions
- Makes careless mistakes despite understanding the subject
5. Hyperactivity and Impulsivity
Hyperactivity
- Fidgets/taps hands or feet
- Leaves seat when remaining seated is expected
- Runs/climbs in inappropriate situations
- Unable to play quietly
- Acts as if “driven by a motor”
- Talks excessively
Impulsivity
- Blurts out answers
- Has difficulty waiting for turn
- Interrupts or intrudes on others
Clinical examples
- Interrupts conversations
- Answers before question is completed
- Cannot wait in queues
- Frequently gets out of seat
- Excessive talking
- Intrudes into others’ activities
6. DSM-5 Diagnostic Criteria — VERY HIGH YIELD
A. Symptom threshold
Inattention
≥6 symptoms for children <17 years
≥5 symptoms for age ≥17 years
AND/OR
Hyperactivity/impulsivity
≥6 symptoms for children <17 years
≥5 symptoms for age ≥17 years. (Psychiatry)
B. Duration
Symptoms must persist for:
≥6 months
and be inconsistent with developmental level and negatively affect social/academic/occupational activities.
C. Age of onset
Several symptoms must have been present:
Before age 12 years
Important exam comparison
| DSM edition | Age of onset |
|---|---|
| DSM-IV | Before 7 years |
| DSM-5 | Before 12 years |
The change to <12 years is specifically noted in the AAP guideline. (American Academy of Pediatrics)
7. Multiple Settings — VERY IMPORTANT
Symptoms must occur in:
≥2 settings
Examples:
- Home
- School
- Social environment
- Other activities
Information should ideally come from parents + teachers/school personnel, rather than relying on a single observer. (American Academy of Pediatrics)
Why?
A child who is inattentive only at home may have:
- Family conflict
- Sleep problem
- Anxiety
- Parenting/environmental issue
rather than necessarily having ADHD.
8. Functional Impairment
Symptoms must cause clinically significant impairment.
Assess:
Academic
- Poor grades
- Incomplete work
- Poor organization
- Repeated disciplinary problems
Social
- Difficulty maintaining friendships
- Interrupting
- Aggressive/impulsive interactions
- Rejection by peers
Family
- Frequent arguments
- Difficulty following instructions
- Excessive parental stress
Safety
- Traffic accidents
- Risk-taking
- Injuries
- Impulsive behavior
9. ADHD Presentations
DSM-5 uses presentations, not the older “types.”
1. Predominantly inattentive presentation
Inattention criteria fulfilled, but hyperactivity/impulsivity threshold not met.
Typical:
Quiet → daydreaming → forgetful → poor organization → academic difficulty
2. Predominantly hyperactive/impulsive presentation
Hyperactivity/impulsivity criteria fulfilled, but inattention threshold not met.
Typical:
Restless → impulsive → interrupts → cannot wait → excessive talking
3. Combined presentation
Criteria fulfilled for:
Both inattention + hyperactivity/impulsivity
This is a very common exam question.
10. Severity
DSM-5:
Mild
Few symptoms beyond minimum required and relatively minor impairment.
Moderate
Symptoms/impairment between mild and severe.
Severe
Many symptoms beyond diagnostic threshold and/or marked impairment.
11. Clinical Evaluation
There is no single laboratory test, imaging test, EEG, or biomarker that diagnoses ADHD.
Diagnosis is clinical.
AAP recommends evaluation of children/adolescents 4–18 years presenting with academic/behavioral problems and symptoms of inattention, hyperactivity, or impulsivity. (American Academy of Pediatrics)
Step 1 — Detailed history
Developmental history
- Pregnancy
- Birth
- Prematurity
- Neonatal complications
- Developmental milestones
- Language development
Behavioral history
- Onset
- Duration
- Situations
- Severity
- Triggers
- Functional consequences
School history
- Academic performance
- Teacher feedback
- Attendance
- Homework
- Classroom behavior
- Learning difficulties
Family history
- ADHD
- Learning disorder
- Psychiatric illness
- Substance use
Sleep
Ask specifically about:
- Sleep duration
- Snoring
- Apnea
- Restless sleep
- Excessive daytime sleepiness
12. Physical Examination
Usually normal.
Look for conditions that can mimic or contribute to symptoms:
- Hearing impairment
- Visual impairment
- Neurologic abnormalities
- Thyroid disease
- Sleep-disordered breathing
- Tics
- Medication effects
- Growth abnormalities
13. Rating Scales
Useful for screening, quantifying symptoms, and monitoring, but:
Rating scale ≠ diagnosis
Examples:
- Vanderbilt ADHD Diagnostic Rating Scale
- Conners Rating Scales
- SNAP-IV
Obtain information from:
Parent + teacher
whenever possible.
14. Differential Diagnosis — VERY IMPORTANT
Many conditions can mimic ADHD.
Psychiatric
- Anxiety disorders
- Depression
- Bipolar disorder
- PTSD
- Oppositional defiant disorder
- Conduct disorder
- Adjustment disorder
Developmental
- Intellectual disability
- Specific learning disorder
- Language disorder
- Autism spectrum disorder
Medical
- Hearing impairment
- Visual impairment
- Epilepsy
- Hyperthyroidism
- Sleep apnea
- Iron deficiency
- Medication effects
Environmental
- Family conflict
- Abuse/neglect
- Psychosocial stress
- Inadequate educational environment
15. ADHD vs Normal Activity
Normal child
Symptoms:
- Situation-dependent
- Developmentally appropriate
- Intermittent
- No major functional impairment
ADHD
Symptoms:
- Persistent
- Developmentally inappropriate
- Present across settings
- Cause significant impairment
16. Comorbidities — HIGH-YIELD
ADHD commonly occurs with other disorders.
AAP specifically recommends screening for emotional/behavioral, developmental, and physical comorbidities. (American Academy of Pediatrics)
Important comorbidities
| Comorbidity | Clinical importance |
|---|---|
| Oppositional defiant disorder | Very common |
| Conduct disorder | Important behavioral complication |
| Specific learning disorder | Academic problems |
| Anxiety disorders | Common |
| Depression | Especially adolescence |
| Autism spectrum disorder | Neurodevelopmental overlap |
| Language disorder | Can mimic inattention |
| Tic disorders/Tourette syndrome | Important treatment consideration |
| Sleep disorders | Can mimic/worsen ADHD |
| Substance use disorder | Particularly adolescence |
| Intellectual disability | Diagnostic challenge |
17. ADHD and Learning Disorder
This is a very important distinction.
A child may have:
ADHD + specific learning disorder
rather than poor academic performance being entirely due to ADHD.
Examples:
- Dyslexia
- Dyscalculia
- Written-expression disorder
Therefore, persistent academic difficulty despite adequate ADHD treatment warrants evaluation for a learning disorder.
18. Natural History
ADHD often begins in childhood and may persist into adolescence/adulthood.
With age:
Preschool
- Marked hyperactivity
- Impulsivity
- Difficult behavior
School age
- Academic problems
- Poor concentration
- Classroom disruption
- Peer difficulties
Adolescence
Hyperactivity may become less obvious, while:
- Inattention
- Poor organization
- Impulsivity
- Academic difficulties
- Risk-taking
may become more prominent.
Adulthood
Possible manifestations:
- Poor organization
- Procrastination
- Difficulty sustaining attention
- Impulsivity
- Occupational difficulties
19. Consequences of Untreated ADHD
Possible consequences include:
- Academic underachievement
- School disciplinary problems
- Social difficulties
- Family conflict
- Low self-esteem
- Accidental injuries
- Risk-taking
- Substance use
- Driving-related problems in adolescents
- Occupational difficulties later in life
20. Treatment — Core Principle
Treatment should be:
Multimodal + individualized + longitudinal
Components:
- Psychoeducation
- Behavioral interventions
- School interventions
- Pharmacotherapy when indicated
- Treatment of comorbidities
- Regular monitoring
21. Treatment According to Age
4–5 years
First-line
Parent training in behavior management (PTBM) / behavioral classroom interventions
AAP recommends behavioral treatment first when available. (American Academy of Pediatrics)
Medication
If:
- Moderate–severe impairment persists
- Behavioral treatment insufficient
→ Methylphenidate may be considered.
Medication before age 6 requires particularly careful risk-benefit consideration. (American Academy of Pediatrics)
22. Age 6–11 years
Treatment can include:
Medication + behavioral intervention
AAP recommends FDA-approved medication and/or evidence-based parent/teacher behavioral interventions, preferably combined. (American Academy of Pediatrics)
23. Adolescents 12–18 years
Main treatment
Medication
plus:
- Behavioral intervention
- Organizational skills training
- School support
- Family involvement
Adolescent assent should be incorporated into treatment decisions. (American Academy of Pediatrics)
24. Pharmacological Treatment
A. Stimulants
1. Methylphenidate
Common first-line stimulant.
Mechanism:
Inhibits dopamine and norepinephrine reuptake → increases catecholaminergic signaling.
Clinical effects:
- ↑ attention
- ↓ hyperactivity
- ↓ impulsivity
AAP notes that stimulants remain first-line medications for ADHD. (AAP)
2. Amphetamine preparations
Mechanisms include:
- Increased catecholamine release
- Reuptake inhibition
Availability varies by country.
25. Stimulant Adverse Effects
Common
- ↓ Appetite
- Weight loss
- Abdominal pain
- Headache
- Insomnia
- Irritability
Cardiovascular
- Mild ↑ heart rate
- Mild ↑ blood pressure
Less common/important
- Tics may emerge or fluctuate
- Mood symptoms
- Growth effects
Rare but important
- Serious cardiovascular events are very uncommon but require appropriate clinical assessment.
26. Stimulant Monitoring
Before treatment:
- Height
- Weight
- BP
- Pulse
- Cardiovascular history
- Family history of sudden cardiac death/serious cardiac disease
During treatment:
Growth + appetite + BP/HR + sleep + behavioral response
Monitor school and social functioning, not merely symptom scores.
27. Non-stimulant medications
Important examples:
Atomoxetine
Selective:
Norepinephrine reuptake inhibitor
Advantages:
- Non-stimulant
- Useful when stimulant is poorly tolerated
- Useful in some patients with substance-use concerns/tic disorders
Adverse effects:
- GI symptoms
- Decreased appetite
- Fatigue
- Possible suicidal ideation warning
- Rare liver injury
α2-adrenergic agonists
Guanfacine
Clonidine
Mechanism:
α2-adrenergic agonism → improves prefrontal cortical regulation.
Particularly useful for:
- Hyperactivity/impulsivity
- Tics
- Sleep difficulties
- As adjuncts to stimulants
Adverse effects:
- Sedation
- Fatigue
- Hypotension
- Bradycardia
Do not abruptly discontinue because of risk of rebound hypertension.
28. Behavioral Treatment
Important interventions:
Parent training
Parents learn:
- Positive reinforcement
- Consistent consequences
- Clear commands
- Token/reward systems
- Predictable routines
- Immediate feedback
Classroom interventions
- Preferential seating
- Short instructions
- Break tasks into smaller components
- Frequent feedback
- Reinforcement systems
- Reduced distractions
- Organizational support
29. School-Based Management
Very important because ADHD is fundamentally a functional disorder.
Helpful strategies:
Short task → immediate feedback → positive reinforcement → structured routine
Examples:
- Written instructions
- Assignment organizers
- Extra time where appropriate
- Frequent breaks
- Seating near teacher
- Daily report card
- Individualized educational support when indicated
30. Diet and ADHD
Important exam point
There is no routine ADHD-specific diet that replaces evidence-based treatment.
Avoid claiming:
“Sugar causes ADHD.”
Evidence does not support sugar as the primary cause of ADHD.
Broad elimination diets should not be routinely prescribed without a specific indication.
31. Common Exam Traps
Trap 1
Symptoms only at school → ADHD?
❌ Not enough.
Need evidence of impairment/symptoms in ≥2 settings.
Trap 2
Child has poor grades → ADHD?
❌ No.
Consider:
- Learning disorder
- Intellectual disability
- Language disorder
- Anxiety
- Depression
- Sleep disorder
Trap 3
ADHD diagnosis requires MRI/EEG?
❌ No.
Clinical diagnosis.
Trap 4
ADHD is caused by poor parenting?
❌ No.
Strong genetic/neurobiological contribution.
Trap 5
Onset before 7 years?
❌ Old DSM-IV criterion.
Current DSM-5:
Several symptoms before age 12 years.
(American Academy of Pediatrics)
Trap 6
One setting is sufficient?
❌ No.
Symptoms/impairment should be demonstrated in ≥2 settings. (American Academy of Pediatrics)
32. ADHD — One-Page Diagnostic Algorithm
Suspected ADHD
↓
1. Identify symptoms
Inattention / hyperactivity / impulsivity
↓
2. ≥6 months?
↓
3. DSM-5 symptom threshold?
- <17 years → ≥6
- ≥17 years → ≥5
↓
4. Several symptoms before age 12?
↓
5. ≥2 settings?
Home + school/social
↓
6. Significant impairment?
↓
7. Exclude alternative explanations
- Anxiety
- Depression
- Learning disorder
- ASD
- Sleep disorder
- Medical causes
- Psychosocial problems
↓
8. Screen for comorbidities
↓
Diagnosis of ADHD
33. Treatment Algorithm — Exam Version
Age 4–5
Behavioral therapy/PTBM
↓
If persistent moderate–severe impairment:
Consider methylphenidate
Age 6–11
Medication ± behavioral intervention
Preferably:
Combined approach
Age 12–18
Medication ± behavioral intervention
with adolescent participation/assent.
AAP’s age-specific recommendations follow this framework. (American Academy of Pediatrics)
34. Most Important Numbers to Remember
| Point | Number |
|---|---|
| Minimum symptom duration | ≥6 months |
| Diagnostic age range in AAP guideline | 4–18 yr |
| DSM-5 onset | Before 12 yr |
| Symptoms required, <17 yr | ≥6 |
| Symptoms required, ≥17 yr | ≥5 |
| Settings | ≥2 |
| Main stimulant | Methylphenidate |
| Preschool first-line | Behavioral therapy/PTBM |
35. Viva Pearls
Q. What is ADHD?
A neurodevelopmental disorder characterized by persistent developmentally inappropriate inattention and/or hyperactivity-impulsivity causing functional impairment.
Q. Is ADHD purely a behavioral disorder?
No. It is a neurodevelopmental disorder with strong genetic and neurobiological contributions.
Q. What is essential before diagnosing ADHD?
Demonstrate symptoms/impairment in ≥2 settings and exclude alternative explanations.
Q. What is the age-of-onset criterion?
Several symptoms must be present before 12 years.
Q. Most important comorbid behavioral disorder?
Oppositional defiant disorder is very common; conduct disorder is also important.
Q. First-line pharmacological treatment?
Stimulants, particularly methylphenidate.
Q. First-line treatment in preschool ADHD?
Parent training/behavioral intervention.
Q. Is there a diagnostic blood test?
No.
Q. Should teachers be involved in diagnosis?
Yes. Teacher/school information is particularly important because symptoms must be assessed across settings. (American Academy of Pediatrics)
Core references
- Nelson Textbook of Pediatrics, latest available edition — ADHD/behavioral and developmental disorders.
- Wolraich ML, et al. Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of ADHD in Children and Adolescents. Pediatrics. 2019;144:e20192528. (American Academy of Pediatrics)
- DSM-5/DSM-5-TR criteria for ADHD.
- American Academy of Pediatrics ADHD guidance. (AAP)
- Standard child and adolescent psychiatry texts covering neurodevelopmental disorders and psychopharmacology.