What are the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) criteria for Attention Deficit Hyperactivity Disorder (ADHD)?

DSM-5 Diagnostic Criteria for ADHD

The DSM-5 requires at least 6 symptoms (5 for adults ≥17 years) from either the inattention or hyperactivity-impulsivity domain, persisting for at least 6 months, with onset before age 12, present in two or more settings, causing functional impairment, and not better explained by another mental disorder. 1, 2

Core Symptom Domains and Presentations

The DSM-5 defines ADHD across two primary symptom dimensions that determine clinical presentation 1:

Inattention Symptoms (6 required for children <17 years; 5 for adults ≥17 years)

• Difficulty sustaining attention on tasks or activities 3
• Appearing preoccupied with difficulty shifting focus even when directly addressed 3
• Poor attention to detail leading to careless mistakes in work or activities 3
• Difficulty completing tasks due to becoming distracted or sidetracked 3
• Organizational challenges including chronic lateness, messiness, or disorganized work 3
• Reluctance to engage in tasks requiring sustained mental effort 3

Hyperactivity-Impulsivity Symptoms (6 required for children <17 years; 5 for adults ≥17 years)

• The DSM-5 includes hyperactive and impulsive behaviors that must be present for at least 6 months 1, 2
• Research indicates impulsivity items better represent adolescent deficits than hyperactivity items 4

Three Clinical Presentations

The DSM-5 classifies ADHD into four diagnostic categories 1:

1. Predominantly Inattentive Presentation (314.00 [F90.0]): Meets inattention criteria but not hyperactivity-impulsivity criteria 1
2. Predominantly Hyperactive-Impulsive Presentation (314.01 [F90.1]): Meets hyperactivity-impulsivity criteria but not inattention criteria 1
3. Combined Presentation (314.01 [F90.2]): Meets both inattention and hyperactivity-impulsivity criteria 1
4. Other Specified and Unspecified ADHD (314.01 [F90.8]): For presentations that don't fully meet criteria but cause impairment 1

Important caveat: These presentations have marked longitudinal instability and function more as clinical shorthand for current symptom levels rather than discrete diagnostic subgroups 5

Mandatory Temporal and Developmental Requirements

Age of Onset

• Symptoms must have been present before age 12 years 1, 2
• For adolescents and adults, clinicians must establish retrospective evidence of childhood onset even when documentation is limited 6

Duration

• Symptoms must persist for at least 6 months 2, 7
• This duration requirement distinguishes ADHD from transient behavioral problems 3

Functional Impairment Across Settings

Critical requirement: Impairment must be documented in more than one major setting (social, academic, or occupational) 1, 2:

• Information must be obtained from multiple sources: parents/guardians, teachers, school personnel, and mental health clinicians 1
• Evidence must demonstrate that symptoms interfere with or reduce quality of functioning 3
• Common pitfall: Failing to gather sufficient information from multiple settings before concluding criteria are not met 6

Exclusion Criteria and Differential Diagnosis

Symptoms must not be better explained by another mental disorder 3:

• Rule out depression, anxiety, psychotic disorders, bipolar disorder, personality disorders 3
• Consider medical conditions through history, physical examination, and laboratory tests 3
• Other differential diagnoses include learning disabilities, narcolepsy, and borderline intellectual functioning 3
• For adolescents, strongly consider substance use, depression, and anxiety as alternative or comorbid conditions 6

Mandatory Comorbidity Screening

Systematic screening for comorbid conditions is essential, not optional 2, 6:

• Screen for anxiety, depression, oppositional defiant disorder, and conduct disorder 2
• The majority of children with ADHD meet criteria for another mental disorder 6
• Critical pitfall: Withholding beneficial behavioral interventions while waiting to establish formal diagnosis 6

Age-Specific Diagnostic Considerations

Preschool-Aged Children (4-5 years)

• DSM-5 criteria can appropriately identify ADHD in preschool-aged children 1, 7
• Challenge: Observing symptoms across multiple settings, particularly for children not attending preschool or childcare 1, 6
• Behaviors indicative of ADHD in older children may be developmentally appropriate in preschoolers 7
• Parent training in behavior management (PTBM) is recommended as primary intervention even before diagnosis is verified 1, 6

Adolescents

• DSM-5 includes developmental symptom descriptors referencing adolescent manifestations 4
• These descriptors led to slightly more inattention symptom endorsement but minimal clinical impact 4
• Must establish that manifestations were present before age 12 despite limited retrospective documentation 6

Adults (≥17 years)

• Symptom threshold reduced to 5 symptoms (instead of 6) for each domain 3, 8
• Best symptomatic cut-offs are 5 inattention symptoms and 4 hyperactivity-impulsivity symptoms 8
• DSM-5 criteria result in approximately 27% increase in expected prevalence compared to DSM-IV 8
• Inattentive symptoms remain the most important predictors of impairment in adults 8

Diagnostic Assessment Tools

• DSM-based ADHD rating scales should be used to systematically collect information from parents and teachers 1
• Normative data available for ages 5-18 years on DSM-5-based scales 1
• For adults, the Adult ADHD Self-Report Scale (ASRS-V1.1) is the first-line screening tool 3
• A positive screen requires "often" or "very often" checked for 4 or more of 6 questions in Part A 3
• Neuropsychological testing does not improve diagnostic accuracy in most cases, though it may clarify learning strengths and weaknesses 1

Subthreshold ADHD and Treatment Without Full Criteria

Behavioral interventions like PTBM are beneficial for children with ADHD-like behaviors who don't meet full criteria 6:

• These programs don't require a specific diagnosis to benefit the family 6
• This approach treats functionally impairing symptoms while avoiding premature diagnostic labeling 6
• Before concluding criteria aren't met, review diagnostic criteria closely and obtain more information from additional settings 6

Key Clinical Pitfalls to Avoid

• Failing to gather information from multiple sources and contexts before diagnosis 2, 6
• Underdiagnosing girls who present with predominantly inattentive symptoms 2
• Assigning ADHD diagnosis when symptoms are better explained by trauma, substance use, or other psychiatric conditions 6
• Failing to screen for comorbid conditions that may explain or coexist with symptoms 2, 6