What are the diagnostic criteria and treatment options for a patient with suspected Attention Deficit Hyperactivity Disorder (ADHD)?

ADHD Diagnosis and Treatment

For any patient with suspected ADHD, initiate a systematic diagnostic evaluation using DSM-5 criteria requiring at least 5 symptoms (adults 17+) or 6 symptoms (children/adolescents) of inattention and/or hyperactivity-impulsivity present for ≥6 months, with documented onset before age 12, functional impairment in at least two settings, and information gathered from multiple sources including parents, teachers, and collateral informants. 1, 2

Diagnostic Criteria and Process

Core DSM-5 Requirements

The diagnosis mandates meeting all of the following criteria:

• Symptom threshold: At least 5 symptoms of inattention and/or hyperactivity-impulsivity for adults (age ≥17 years); 6 symptoms for children and adolescents (age <17 years) 1, 3, 2
• Duration: Symptoms must persist for at least 6 months 1, 2
• Age of onset: Several symptoms must have been present before age 12 years, documented through patient recall, collateral informants, old report cards, or historical records 1, 3, 2
• Pervasiveness: Functional impairment must be documented in at least two independent settings (home, work, school, social relationships) 1, 3, 2
• Exclusion: Symptoms are not better explained by another mental disorder, oppositional behavior, substance use, trauma, or failure to understand instructions 1, 2

Systematic Assessment Approach

Use validated rating scales as screening tools, but never diagnose based on rating scales alone—clinical interview is mandatory:

• For adults: Use the Adult ADHD Self-Report Scale (ASRS-V1.1) Part A as initial screening (positive if 4+ of 6 questions marked "often" or "very often"), followed by Part B for comprehensive symptom assessment 1, 3
• For children/adolescents: Use DSM-IV-based validated scales such as ADHD Rating Scale-IV or Conners Comprehensive Behavior Rating Scales 1
• Obtain collateral information from family members, partners, teachers, or close friends to corroborate symptoms, as adults often minimize their difficulties 1, 3

Critical Differential Diagnosis

Before confirming ADHD, systematically rule out conditions that mimic or coexist with ADHD:

• Substance use disorders: Marijuana and stimulants produce identical symptoms to ADHD; reassess after sustained abstinence before diagnosing ADHD 3
• Trauma/PTSD: Can cause hypervigilance, concentration problems, and emotional dysregulation; treat PTSD first, then reassess attention symptoms 3
• Mood and anxiety disorders: Depression and anxiety are highly comorbid with ADHD (present in ~10% of adults with recurrent depression/anxiety); optimize treatment for these conditions before diagnosing ADHD 1, 3
• Sleep disorders, learning disabilities, oppositional defiant disorder, conduct disorder: Screen systematically for these comorbidities 1, 2

Age-Specific Diagnostic Considerations

For preschool-aged children (4-5 years):

• DSM-IV criteria can be applied, but subtypes may not be valid in this age group 1
• Obtain observations from qualified preschool/childcare staff when available 1
• Consider parent-training programs before confirming diagnosis to establish age-appropriate developmental expectations 1

For adolescents:

• Consider substance abuse, depression, and anxiety as alternative or comorbid diagnoses 2
• Note that hyperactive symptoms typically decline while inattentive symptoms persist into adulthood 3

For adults:

• Obtain detailed developmental history focusing on elementary and middle school years to establish childhood onset 3
• Review old report cards, school records, or prior evaluations when available 3
• Assess chronicity and pervasiveness of symptoms throughout the lifespan 3

Common Diagnostic Pitfalls to Avoid

Critical errors that lead to misdiagnosis:

• Relying solely on self-report without collateral information 3, 2
• Not establishing childhood onset before age 12 (this is non-negotiable) 3, 2
• Diagnosing ADHD when symptoms are better explained by substance use, trauma, or mood disorders 3
• Using rating scale scores alone without comprehensive clinical interview 3
• Failing to gather information from multiple sources and contexts 2
• Failing to screen for comorbid conditions 2
• Underdiagnosing girls who present with predominantly inattentive symptoms 2

Treatment Options

Pharmacotherapy

For elementary school-aged children (6-11 years) and adolescents:

• First-line: FDA-approved stimulants (methylphenidate or amphetamine formulations) and/or evidence-based parent/teacher-administered behavior therapy, preferably both 1
• Stimulants show approximately 60% moderate-to-marked improvement rates 3
• Atomoxetine is effective at doses of 1.2-1.8 mg/kg/day (mean ~1.3-1.6 mg/kg/day), administered once daily in the morning or as divided doses 4

For preschool-aged children (4-5 years):

• First-line: Evidence-based parent- and/or teacher-administered behavior therapy 1, 5
• Second-line: Methylphenidate may be prescribed only if behavioral interventions do not provide significant improvement and there is moderate-to-severe continuing functional disturbance 1, 5

For adults:

• First-line: Stimulants (amphetamine or methylphenidate formulations), titrated to maximum benefit with minimum adverse effects 3, 6, 7
• Alternative medications: Atomoxetine (effective at ~95 mg/day mean dose), viloxazine, or bupropion for adults unable to take stimulants or with concurrent anxiety/depression 3, 4, 7
• Combination of medication plus psychotherapy is more effective than either alone 3

Behavioral Interventions

Evidence-based behavioral therapy should be implemented, particularly:

• Parent Training in Behavior Management (PTBM) for preschool and elementary-aged children 1, 5
• Teacher-administered behavioral supports in classroom settings 1
• Psychoeducation and environmental modifications for all age groups 3, 6

Monitoring and Chronic Disease Management

Recognize ADHD as a chronic condition requiring ongoing care:

• Follow principles of the chronic care model and medical home 1
• Regular monitoring to assess treatment response, side effects, and functional outcomes 3, 5
• For stimulant therapy, consider controlled substance agreements and prescription drug monitoring programs to monitor for misuse or diversion 7
• Titrate medication doses week by week according to response 6

Referral Considerations

Refer to psychiatrist, developmental-behavioral specialist, or neuropsychologist when:

• Clinical picture is complex, atypical, or involves significant comorbidity 3
• Complex comorbidity requires specialized medication management 3
• Further cognitive assessment is needed and not available through the education system 1