DSM-5 Criteria for ADHD Diagnosis
The DSM-5 diagnostic criteria for ADHD require an ongoing pattern of inattention and/or hyperactivity-impulsivity symptoms persisting for at least 6 months, with multiple symptoms present before age 12, occurring in 2 or more settings, and causing functional impairment. 1
Core Diagnostic Requirements
- Symptom Threshold:
- Duration: Symptoms must persist for at least 6 months
- Age of onset: Symptoms must have been present before age 12 (changed from age 7 in DSM-IV) 3, 1
- Multiple settings: Symptoms must occur in two or more settings (e.g., home, school, work)
- Functional impairment: Symptoms must interfere with daily functioning 1
- Alternative causes: Other conditions that might explain symptoms must be ruled out 3, 1
Symptom Categories
Inattention Symptoms
- Poor attention to detail or making careless mistakes
- Difficulty sustaining attention in tasks or activities
- Not listening when spoken to directly
- Failing to follow through on instructions or complete tasks
- Difficulty organizing tasks and activities
- Avoiding tasks requiring sustained mental effort
- Losing things necessary for tasks or activities
- Being easily distracted by extraneous stimuli
- Being forgetful in daily activities 1
Hyperactivity-Impulsivity Symptoms
- Fidgeting or tapping hands/feet or squirming in seat
- Leaving seat when remaining seated is expected
- Running or climbing excessively (in adults: feeling restless)
- Inability to engage in leisure activities quietly
- Being "on the go" or acting as if "driven by a motor"
- Talking excessively
- Blurting out answers before questions are completed
- Difficulty waiting turn
- Interrupting or intruding on others 1
ADHD Presentations
The DSM-5 defines four presentations of ADHD:
- Predominantly Inattentive Presentation: Meets criteria for inattention but not hyperactivity-impulsivity
- Predominantly Hyperactive-Impulsive Presentation: Meets criteria for hyperactivity-impulsivity but not inattention
- Combined Presentation: Meets criteria for both inattention and hyperactivity-impulsivity
- Other Specified and Unspecified ADHD: For cases that don't fully meet criteria but show significant symptoms 1
Diagnostic Evaluation Process
A comprehensive evaluation should include:
- Structured clinical interview
- Collateral information from multiple sources (parents/guardians, teachers, spouse/partner)
- Standardized rating scales
- Screening for comorbid conditions 3, 1
Important Clinical Considerations
- Symptoms must be excessive for developmental (not just chronological) age 1
- ADHD rarely occurs in isolation - screening for comorbid conditions is essential 3, 1
- Self-diagnosis without proper evaluation is insufficient; screening tools alone cannot establish diagnosis 1
- The DSM-5 subtype model has limitations, including marked longitudinal instability of all three subtypes 4
- The lower symptom threshold for adults (5+ symptoms) is supported by research, as adults are more likely to present with inattentive symptoms 1, 5, 6
Pitfalls to Avoid
- Failing to obtain information from multiple sources and settings
- Not screening for comorbid conditions, which can worsen outcomes 3, 1
- Overlooking functional impairment (symptoms without impairment do not meet diagnostic criteria)
- Not ruling out alternative explanations for symptoms (medical conditions, other psychiatric disorders, substance use) 1
- Relying solely on self-report or screening tools without comprehensive evaluation 1
The DSM-5 criteria represent an evolution from previous versions, with changes including the age of onset requirement (from 7 to 12 years) and the reduced symptom threshold for adults, which research suggests may help identify more adults with ADHD while preventing missed diagnoses 6.