What are the clinical diagnostic criteria for Attention Deficit Hyperactivity Disorder (ADHD)?

Clinical Diagnostic Criteria for ADHD

The diagnosis of ADHD requires meeting the DSM-5 criteria, including documentation of at least 5 symptoms of inattention and/or hyperactivity-impulsivity (for adults age 17+) or at least 6 symptoms (for children under 17), with symptoms present before age 12, persisting for at least 6 months, occurring in multiple settings, and causing functional impairment. 1

Core Diagnostic Requirements

Essential Criteria

• Duration: Symptoms must persist for at least 6 months 1
• Age of onset: Several symptoms must be present before age 12 1
• Multiple settings: Symptoms must be present in 2 or more settings (e.g., home, school, work) 1
• Functional impairment: Clear evidence that symptoms interfere with or reduce quality of functioning 1
• Symptom threshold:
  • Ages 17 and older: At least 5 symptoms from either category
  • Children under 17: At least 6 symptoms from either category 1

Symptom Categories

Inattentive Symptoms 1

1. Poor attention to detail/makes careless mistakes
2. Difficulty sustaining attention on tasks
3. Appears not to listen when spoken to directly
4. Difficulty completing tasks (gets distracted/sidetracked)
5. Organizational challenges (chronic lateness, messiness)
6. Avoids tasks requiring sustained mental effort
7. Loses necessary items for tasks/activities
8. Easily distracted by external stimuli
9. Forgetful in daily activities

Hyperactive-Impulsive Symptoms 1

1. Fidgets or taps hands/feet
2. Difficulty remaining seated when expected
3. Restlessness or feeling agitated
4. Loud or disruptive during quiet activities
5. Excessive movement ("on the go")
6. Talks excessively
7. Blurts out answers before questions completed
8. Difficulty waiting turn
9. Interrupts or intrudes on others

ADHD Subtypes 1

• Predominantly Inattentive: ≥5 inattentive symptoms, <5 hyperactive-impulsive symptoms
• Predominantly Hyperactive-Impulsive: ≥5 hyperactive-impulsive symptoms, <5 inattentive symptoms
• Combined Type: ≥5 symptoms from both categories

Diagnostic Process

Required Assessment Components 1, 2

1. Structured clinical interview with patient

2. Collateral information from:

   • Parents/guardians (for children/adolescents)
   • Teachers/school personnel (at least 2 sources for children)
   • Spouse/partner/close family (for adults)
   • Other observers in different settings

3. Standardized rating scales:

   • Adult ADHD Self-Report Scale (ASRS-V1.1) for initial screening 1, 2
   • DSM-5-based comprehensive rating scales 1

4. Rule out alternative explanations for symptoms:

   • Medical conditions
   • Other psychiatric disorders
   • Substance use/medication effects
   • Environmental factors 1

Special Considerations by Age Group

Children (Ages 4-11) 1

• Evaluation should be initiated for any child presenting with academic/behavioral problems and symptoms of inattention, hyperactivity, or impulsivity
• For preschool children (4-5 years), behavioral interventions should be first-line treatment
• Symptoms often more apparent in structured settings like classrooms

Adolescents (Ages 12-17) 1

• Hyperactive symptoms may be less overt than in children
• Must confirm presence of symptoms before age 12
• Increased risk for:
  • Substance use (which can mimic ADHD symptoms)
  • Mood and anxiety disorders
  • Risky behaviors
• Adolescents may minimize their symptoms in self-reports

Adults 3

• Hyperactivity often internalized as inner restlessness
• Inattention may be masked by anxiety or compensatory strategies
• Functional impairment in academic, occupational, and social domains is key to diagnosis
• Retrospective assessment of childhood symptoms is essential

Comorbidity Assessment

Required Screening 1, 2

• Emotional/behavioral conditions:

  • Anxiety disorders
  • Depression
  • Oppositional defiant disorder
  • Conduct disorders
  • Substance use disorders

• Developmental conditions:

  • Learning disabilities
  • Language disorders
  • Autism spectrum disorders

• Physical conditions:

  • Sleep disorders (including sleep apnea)
  • Tic disorders

Common Diagnostic Pitfalls

1. Failing to obtain multi-informant data - Relying solely on patient self-report can lead to under or over-diagnosis 1, 2

2. Missing comorbid conditions - ADHD rarely occurs in isolation; untreated comorbidities can worsen outcomes 1

3. Inadequate developmental context - Symptoms must be excessive for developmental (not just chronological) age 1

4. Self-diagnosis without proper evaluation - Screening tools alone are insufficient for diagnosis 2

5. Overlooking functional impairment - Symptoms without impairment do not meet diagnostic criteria 1

6. Attributing symptoms to other conditions - Particularly in adults, ADHD symptoms may be misattributed to anxiety or depression 3

The diagnostic process for ADHD requires thorough, systematic assessment across multiple domains and settings. While no single laboratory or neuropsychological test can definitively diagnose ADHD, adherence to the structured DSM-5 criteria with comprehensive information gathering provides the most accurate approach to diagnosis.