What are the diagnostic criteria and treatment options for Adult Attention Deficit Hyperactivity Disorder (ADHD)?

Adult ADHD Diagnostic Criteria

Adults with ADHD must meet DSM-5 criteria requiring at least 5 symptoms of inattention and/or 5 symptoms of hyperactivity-impulsivity (rather than the 6 required for children), with documented onset before age 12, functional impairment in at least two settings, and systematic exclusion of alternative diagnoses. 1, 2

Core Diagnostic Requirements

Symptom Threshold and Onset

• Adults require only 5 symptoms from either the inattention category or hyperactivity-impulsivity category (or both), persisting for at least 6 months 1, 2
• Symptom onset before age 12 is mandatory, even when retrospective documentation is limited—this must be established through patient recall, collateral informants, or historical records 3, 1
• Symptoms must cause clear functional impairment and not be better explained by another mental disorder 1, 2

Multi-Setting Documentation

• Functional impairment must be documented in at least two independent settings (work, home, social relationships, academic) using information from multiple sources 3, 1
• Collateral information from family members, partners, or close friends is essential since adults often minimize their own symptoms 4, 2

Clinical Presentation Differences in Adults

Symptom Evolution from Childhood

• Hyperactivity becomes internalized in adults, manifesting as inner restlessness, difficulty relaxing, or feeling "driven by a motor" rather than overt physical hyperactivity 5
• Inattention symptoms persist and may be masked by anxiety or obsessive-like compensation strategies developed over years 5
• Emotional dysregulation and executive dysfunction are prominent features in adults, though not part of formal DSM criteria 5

Common Adult Manifestations

• Chronic disorganization, difficulty completing tasks, poor time management 5, 6
• Impulsive decision-making affecting finances, relationships, and career 6
• Mood lability, low stress tolerance, and quick temper 6

Systematic Diagnostic Process

Step 1: Structured Assessment Tools

• Adult ADHD Self-Report Scale (ASRS) for initial screening in primary care 1, 2
• Conners Adult ADHD Rating Scales (CAARS) for comprehensive symptom assessment with validated normative data 7, 8, 2
• Rating scales systematically collect symptom information but do not diagnose ADHD by themselves—clinical interview is mandatory 7

Step 2: Establish Childhood Onset

• Obtain detailed developmental history focusing on elementary and middle school years 3
• Review old report cards, school records, or prior evaluations if available 3
• Interview parents or siblings who can recall childhood behaviors 2
• Critical pitfall: Failing to establish pre-age-12 onset invalidates the diagnosis regardless of current symptoms 3

Step 3: Document Current Functional Impairment

• Assess specific impairments in occupational performance (job loss, underemployment, frequent job changes) 5, 2
• Evaluate relationship difficulties (divorce, conflict, social isolation) 5
• Review academic struggles if currently in school 5
• Assess financial problems from impulsive spending or disorganization 5

Step 4: Mandatory Comorbidity Screening

Screen systematically for conditions that mimic or coexist with ADHD (present in 80% of adults with ADHD): 5

Psychiatric Comorbidities

• Mood disorders: Major depression and bipolar disorder frequently coexist and can mimic inattention 5, 2
• Anxiety disorders: Worry and rumination can appear as distractibility 5, 2
• Substance use disorders: Extremely common, either as self-medication or consequence of impulsivity 5, 6, 2
• Personality disorders: Borderline and antisocial personality disorders share impulsivity and emotional dysregulation 5

Medical Conditions

• Sleep disorders: Restless leg syndrome and hypersomnolence may share pathophysiology with ADHD 5
• Thyroid dysfunction, sleep apnea, and other medical causes of cognitive impairment 2

Critical Differential Diagnosis Considerations

Conditions That Mimic ADHD

• Substance use (especially marijuana, stimulants) can produce identical symptoms 4
• Trauma and PTSD cause hypervigilance, concentration problems, and emotional dysregulation 4
• Depression and anxiety produce cognitive slowing and distractibility 5, 2
• Bipolar disorder during hypomanic or mixed episodes 5

Diagnostic Algorithm for Ambiguous Cases

1. If substance use is present, reassess after sustained abstinence (minimum 3-6 months) 4
2. If trauma history exists, treat PTSD first and reassess attention symptoms 4
3. If mood/anxiety symptoms are prominent, optimize treatment for these conditions before diagnosing ADHD 5
4. Only diagnose ADHD when symptoms preceded and persist independent of other conditions 1, 2

Common Diagnostic Pitfalls to Avoid

• Relying solely on self-report without collateral information—adults minimize symptoms 4, 7
• Not establishing childhood onset before age 12—this is non-negotiable 3
• Diagnosing ADHD when symptoms are better explained by substance use, trauma, or mood disorders 3
• Using rating scale scores alone without comprehensive clinical interview 7
• Failing to screen for comorbidities that alter treatment approach 4
• Missing compensation strategies that mask symptoms in high-functioning adults 5

Treatment Framework

First-Line Pharmacotherapy

• Stimulants (amphetamine or methylphenidate formulations) are first-line with approximately 60% showing moderate-to-marked improvement versus 10% with placebo 6, 2
• Stimulants should be titrated to maximum benefit with minimum adverse effects 7
• Monitor for misuse/diversion using controlled substance agreements and prescription drug monitoring programs, especially given high comorbidity with substance use disorders 4, 2

Alternative Medications

• Atomoxetine for adults unable to take stimulants or with concurrent anxiety/depression—effective at 1.2-1.8 mg/kg/day divided dosing or once-daily morning dosing 8, 2
• Viloxazine and bupropion are additional non-stimulant options 2
• Atomoxetine has no abuse potential, making it preferable when substance use disorder is present 4, 8

Psychosocial Interventions

• Cognitive behavioral therapy specifically adapted for adult ADHD addresses organizational skills, time management, and emotional regulation 5, 6, 2
• Psychoeducation about the disorder and its impact 5, 6
• Coaching for practical skill development 6
• Combination of medication plus psychotherapy is more effective than either alone 2

Chronic Disease Management

• Recognize ADHD as a chronic condition requiring ongoing monitoring and adjustment 4
• Regular follow-up to assess treatment response, side effects, and functional outcomes 7
• Coordinate care when multiple comorbidities are present 5