What are the diagnostic criteria and evaluation process for Attention Deficit Hyperactivity Disorder (ADHD) in a child?

How to Diagnose ADHD in a Child

Initiate an ADHD evaluation for any child age 4 to 18 years presenting with academic or behavioral problems plus symptoms of inattention, hyperactivity, or impulsivity, then confirm the diagnosis by meeting DSM-5 criteria with documented impairment in at least two settings using information from parents, teachers, and school personnel. 1, 2

When to Start the Evaluation

• Begin evaluation when a child age 4 to 18 years presents with academic difficulties, behavioral problems, and any combination of inattention, hyperactivity, or impulsivity symptoms 1, 3
• Do not diagnose or treat children younger than 4 years (insufficient evidence), though you may refer for parent training in behavior management if severe impairment exists 1

Core Diagnostic Requirements

You must confirm that DSM-5 criteria are met before making the diagnosis: 1, 2

DSM-5 Symptom Criteria

• For Inattentive Type: At least 6 of these symptoms persisting ≥6 months: lacks attention to details/makes careless mistakes, difficulty sustaining attention, doesn't listen when spoken to directly, fails to follow through on tasks, poor organization, avoids tasks requiring sustained mental effort, loses things, easily distracted, forgetful 4
• For Hyperactive-Impulsive Type: At least 6 of these symptoms persisting ≥6 months: fidgets/squirms, leaves seat inappropriately, runs/climbs excessively, difficulty with quiet activities, acts as if "driven by a motor," talks excessively, blurts out answers, can't wait turn, interrupts or intrudes on others 4
• For Combined Type: Both inattentive and hyperactive-impulsive criteria must be met 4

Additional Required Criteria

• Symptoms must have been present before age 12 years 3, 4
• Symptoms must persist for at least 6 months 3
• Impairment must be documented in more than one major setting (home, school, social environments) 1, 3
• Symptoms must cause clinically significant impairment in social, academic, or occupational functioning 4
• Symptoms must not be better explained by another mental disorder 4

Information Gathering Process

Collect information systematically from multiple sources—this is non-negotiable: 1, 2

Required Informants

• Parents or guardians 1, 2
• Teachers and other school personnel 1, 2
• Mental health clinicians involved in the child's care (if applicable) 1
• Self-report from adolescents (age 12-18 years) 2, 3

Assessment Tools to Use

• DSM-5-based ADHD rating scales completed by both parents and teachers—this is the most efficient and effective method 2
• The ADHD Rating Scale-5 is a commonly used, validated tool 2
• Use standardized rating scales rather than relying solely on clinical impression 5

Clinical Interview and Observation

• Conduct clinical interview with parents focusing on symptom onset, duration, settings affected, and functional impairment 2
• Examine and observe the child when possible to assess behavior directly 2
• For preschool children (age 4-5 years), use DSM-based rating scales with preschool norms when available 2

Rule Out Alternative Causes

You must systematically exclude other conditions that could explain the symptoms: 1, 2

• Environmental factors (family problems, environmental changes) 4
• Other primary psychiatric disorders including psychosis 4
• Trauma, anxiety, or mood disorders that better explain symptoms 6
• Learning disabilities or language disorders 1
• Sleep disorders, tics, or seizures 1

Screen for Comorbid Conditions

Screening for comorbidities is mandatory because they occur in the majority of children with ADHD and alter treatment approach: 1

Emotional/Behavioral Conditions to Screen For

• Anxiety disorders 1
• Depression 1
• Oppositional defiant disorder 1
• Conduct disorders 1
• Substance use (especially in adolescents) 1

Developmental Conditions to Screen For

• Learning disabilities 1
• Language disorders 1
• Autism spectrum disorders 1

Physical Conditions to Screen For

• Sleep disorders (sleep apnea) 1
• Tic disorders 1
• Seizures 1

Age-Specific Considerations

Preschool-Aged Children (4-5 years)

• Hyperactive symptoms are often more prominent than inattentive symptoms 3
• Use preschool-normed rating scales when available 2
• Clinical observation is particularly important in this age group 2

School-Aged Children (6-12 years)

• Full DSM-5 criteria apply without modification 3
• Teacher input is critical for documenting school impairment 2

Adolescents (12-18 years)

• Self-report becomes increasingly important 2, 3
• Always assess for substance use as a complicating factor 3
• Screen for depression and suicidal ideation given increased risk 1

Common Diagnostic Pitfalls to Avoid

• Failing to obtain information from multiple settings—relying on a single informant (parent or teacher alone) leads to misdiagnosis 6
• Ignoring functional impairment—symptoms must cause significant impairment, not just be present 6, 4
• Not verifying symptom onset before age 12—this is a required criterion 6, 3
• Misdiagnosing when symptoms are better explained by trauma, anxiety, or other conditions—always rule out alternative causes systematically 6
• Using only subjective impressions without standardized rating scales—this lacks objectivity and reliability 2

When to Refer to Specialists

Refer when: 3

• You are uncertain about the diagnosis
• Multiple complex comorbidities are present
• Standard treatments are ineffective
• The case is particularly complex

Documentation Requirements

Your diagnostic documentation should include: 1, 2

• Specific symptoms meeting DSM-5 criteria
• Evidence of impairment in at least two settings (home and school)
• Verification of symptom onset before age 12 years
• Results from standardized rating scales from parents and teachers
• Comorbid conditions identified or ruled out
• Alternative causes considered and excluded