What diagnostic evaluation and documentation are required for an adult presenting with suspected Attention Deficit Hyperactivity Disorder (ADHD)?

Diagnostic Evaluation for Adult ADHD

When an adult presents with suspected ADHD, you must conduct a comprehensive psychiatric evaluation that documents childhood onset of symptoms (before age 12), current symptom burden (at least 5 symptoms in either domain persisting ≥6 months), and cross-situational functional impairment in at least 2 settings, supplemented by validated rating scales, collateral information, and systematic screening for mimicking conditions and comorbidities. 1

Required Documentation Components

1. Childhood Onset Verification

• Document that ADHD symptoms were present before age 12 years as mandated by DSM-5 criteria 1, 2
• Obtain collateral information from family members, old school records, or report cards to corroborate childhood symptoms 1, 3
• Use the Wender Utah Rating Scale to systematically assess retrospective childhood symptoms 1

2. Current Symptom Assessment

• Document at least 5 symptoms of inattention and/or hyperactivity-impulsivity that have persisted for at least 6 months in adults (note this differs from the 6-symptom threshold in children) 1
• Administer the Adult ADHD Self-Report Scale (ASRS-V1.1) as your primary screening tool—a positive screen requires endorsing "often" or "very often" for 4 or more of 6 questions 1, 4
• Consider the Conners Adult ADHD Rating Scale (CAARS) as an alternative validated instrument 1, 4

3. Cross-Situational Impairment Documentation

• Verify functional impairment in at least 2 settings such as work, home, or social relationships through direct questioning and collateral sources 1, 2
• Document specific examples of how symptoms cause clinically significant impairment in occupational, academic, or social functioning 1, 2

Medical Screening Requirements

Rule Out Medical Mimics

• Perform a focused medical assessment to exclude conditions that mimic ADHD 1
• Consider thyroid function tests to rule out thyroid disorders 1
• Screen for sleep disorders (especially restless leg syndrome and hypersomnolence, which share pathophysiological mechanisms with ADHD) 1, 5
• Evaluate for neurological conditions through history and examination 1

Mandatory Comorbidity Screening

Psychiatric Differential Diagnosis

• Systematically screen for mood disorders (bipolar disorder and major depression) that can mimic ADHD symptoms 1, 4
• Evaluate for anxiety disorders (generalized anxiety, social phobia) which overlap substantially with ADHD presentation 1, 4
• Screen for substance use disorders, which occur in 80% of adults with ADHD either as self-medication attempts or due to impulsivity 1, 5
• Assess for personality disorders, particularly borderline and antisocial personality disorder 1, 5

Why This Matters

• ADHD is comorbid with other psychiatric conditions in 80% of adult cases, making differential diagnosis critical 5
• Comorbid conditions alter treatment approach and must be identified before initiating therapy 1

Diagnostic Algorithm

Follow this step-by-step approach:

1. Initial Screening: Administer ASRS-V1.1 1, 4
2. Comprehensive Clinical Interview: Document childhood onset, current symptoms, and functional impairment 1, 3
3. Collateral Information: Obtain information from family members or review old records 1, 3
4. Structured Rating Scales: Complete ASRS-V1.1 or CAARS and Wender Utah Rating Scale 1, 4
5. Comorbidity Screening: Systematically evaluate for mood, anxiety, substance use, and personality disorders 1, 5
6. Medical Screening: Rule out thyroid disorders, sleep disorders, and neurological conditions 1
7. Functional Impairment Assessment: Document impairment in at least 2 settings 1, 2

Critical Pitfalls to Avoid

• Do not rely solely on rating scale scores—they systematically collect information but cannot diagnose ADHD without comprehensive clinical evaluation 1, 6
• Do not skip collateral information gathering—self-awareness of ADHD symptoms can be difficult for adults who have lived with them since childhood 3
• Do not miss comorbid conditions—failure to screen for anxiety, depression, and substance use will lead to treatment failure 1, 5
• Do not diagnose ADHD when symptoms are better explained by another psychiatric disorder—the substantial symptom overlap requires careful differential diagnosis 4, 5

When to Refer

Consider referral to psychiatry or psychology when:

• Diagnostic uncertainty persists after initial evaluation 1
• Complex comorbid psychiatric conditions are present that require specialized management 1
• Specialized treatment such as cognitive-behavioral therapy or cognitive remediation is needed 1, 5

Adult-Specific Considerations

• In adults, hyperactivity is often internalized rather than externally observable 5
• Inattention symptoms may be masked by anxiety or obsessive-like compensation strategies 5
• Adults often present with emotional dysregulation and executive function deficits beyond core ADHD symptoms 5, 7
• The diagnostic interview should specifically probe for disorganization, poor time management, and procrastination as associated features 7