What is the approach to diagnosing Attention Deficit Hyperactivity Disorder (ADHD) in adults, considering their demographic information, medical history, and potential comorbidities?

Diagnosing Adult ADHD: Structured Clinical Approach

Begin by administering the Adult ADHD Self-Report Scale (ASRS-V1.1) Part A as your initial screening tool—a positive screen requires 4 or more items marked "often" or "very often" out of 6 questions, which takes 3-5 minutes and identifies adults requiring comprehensive evaluation. 1

Initial Screening and Symptom Assessment

• Use the ASRS-V1.1 as your first-line screening instrument to identify patients who warrant full diagnostic evaluation 1, 2
• Adults with ADHD predominantly present with inattentive symptoms rather than hyperactivity, including poor attention to detail, difficulty sustaining concentration, organizational challenges, chronic lateness, and reluctance to engage in tasks requiring sustained mental effort 1
• The Adult ADHD Self-Report Screening Scale for DSM-5 and Conners Adult ADHD Rating Scales provide validated symptom assessment tools 2, 3

Establishing Childhood Onset (Critical Requirement)

You must document that symptoms were present before age 12 through retrospective recall, collateral information from parents or siblings, or review of school records—this is a mandatory DSM-5 criterion that cannot be bypassed. 1, 4, 5

• Use the Wender Utah Rating Scale to systematically assess childhood symptoms retrospectively 4, 6
• Obtain informant interviews from family members who knew the patient during childhood to corroborate early symptom presence 6, 7
• Review available school records, report cards, or teacher comments documenting childhood attention or behavioral problems 7
• Common pitfall: Failing to establish childhood onset leads to misdiagnosis—if symptoms emerged only in adulthood without childhood history, prioritize evaluation for mood disorders, anxiety, or other conditions that mimic ADHD 4

Comprehensive Clinical Interview Requirements

Conduct a detailed clinical interview that documents current symptoms across multiple domains AND verifies functional impairment in at least 2 settings (work, home, social relationships). 1, 4, 5

Current Symptom Documentation

• Inattentive symptoms (need 5+ for adults age ≥17): poor attention to detail, difficulty concentrating, seems preoccupied, difficulty completing tasks, organizational challenges, avoids sustained mental effort, loses belongings, easily distracted, forgetful 1
• Hyperactive-impulsive symptoms (need 5+ for adults age ≥17): frequent fidgeting, difficulty sitting still, inner restlessness, loud/disruptive behavior, always "on the go," talks excessively, interrupts others 1
• Symptoms must persist for at least 6 months and be present continuously, not episodically 1

Functional Impairment Verification

• Document specific examples of how symptoms interfere with interpersonal relationships, occupational performance, or daily functioning 1, 4
• Obtain collateral information from spouse, coworkers, or close contacts to verify impairment across settings 4, 7

Mandatory Differential Diagnosis and Comorbidity Screening

Screen systematically for conditions that mimic or co-occur with ADHD before confirming the diagnosis—approximately 10% of adults with recurrent depression/anxiety have undiagnosed ADHD, and missing comorbidities leads to treatment failure. 1, 4

Primary Psychiatric Differentials to Rule Out

• Bipolar disorder: Look for episodic mood changes, grandiosity during manic phases, and racing thoughts that follow a temporal pattern tied to mood episodes (not continuous like ADHD) 4
• Major depression and anxiety disorders: These share inattention and concentration difficulties but lack the childhood onset and pervasive hyperactivity/impulsivity of ADHD 1, 4
• Substance use disorders: Obtain urine drug screens before confirming ADHD diagnosis, as marijuana and other substances produce symptoms that mimic ADHD 1, 4
• Personality disorders: Distinguish chronic interpersonal dysfunction from ADHD-related impulsivity 4

Medical Conditions That Mimic ADHD

• Sleep apnea: Causes daytime fatigue, inattention, and cognitive slowing that improves with CPAP treatment 4
• Thyroid dysfunction: Both hyper- and hypothyroidism produce concentration difficulties and mood changes 4

Critical Diagnostic Pitfalls

• Distinguish episodic from continuous symptoms: If symptoms are episodic rather than chronic, suspect mood disorders rather than ADHD 4
• Missing substance-induced symptoms: Always obtain drug screens, as stimulant-seeking patients may feign symptoms to obtain medication 1, 4
• Overlooking trauma history: Screen for PTSD and toxic stress, which can produce attention deficits that mimic ADHD 1

Comorbidity Assessment Protocol

Screen all adults being evaluated for ADHD for depression, anxiety disorders, substance use disorders, and learning disabilities—these comorbidities occur in the majority of ADHD patients and fundamentally alter treatment approach. 1, 2

• Depression occurs in approximately 9% of ADHD patients and often requires treatment before ADHD symptoms can be adequately managed 1
• Anxiety disorders occur in approximately 14% of ADHD patients 1, 8
• Around 10% of adults with recurrent depression/anxiety have underlying ADHD that must be addressed for optimal treatment response 1
• Clinical pearl: Treatment of depression and anxiety will likely be inadequate to restore optimal functioning if comorbid ADHD remains unaddressed 1

Diagnostic Algorithm Summary

1. Screen with ASRS-V1.1 (positive = 4+ items marked often/very often) 1
2. Verify childhood onset before age 12 using Wender Utah Rating Scale, collateral informants, and school records 4, 6
3. Document current symptoms (5+ inattentive and/or hyperactive-impulsive symptoms for ≥6 months) 1
4. Confirm functional impairment in 2+ settings through direct interview and collateral sources 1, 4
5. Rule out mimicking conditions (bipolar disorder, substance use, sleep apnea, thyroid dysfunction) with targeted screening and drug testing 4
6. Screen for comorbidities (depression, anxiety, substance use, learning disabilities) that require concurrent treatment 1, 2
7. Ensure symptoms are not better explained by another mental disorder, oppositional behavior, or failure to understand tasks 1

Documentation Requirements

• Complete the diagnostic criteria checklist per DSM-5 specifications 1, 5
• Document specific functional impairments with concrete examples from work, home, and social domains 1, 4
• Record collateral information sources and their observations 4, 7
• Note results of comorbidity screening and any differential diagnoses considered 4, 2