ADHD Assessment in Adults
Adults suspected of ADHD require a comprehensive psychiatric evaluation that documents childhood-onset symptoms (before age 12), uses validated rating scales like the Adult ADHD Self-Report Scale (ASRS-V1.1), obtains collateral information from family or partners, and systematically screens for psychiatric comorbidities and substance use disorders. 1
Core Diagnostic Components
Clinical Interview Requirements
The diagnostic evaluation must establish three critical elements through direct clinical assessment 1:
- Childhood onset documentation: Confirm ADHD symptoms were present before age 12 years, as mandated by DSM-5 criteria 1
- Current symptom assessment: Identify at least 5 symptoms of inattention and/or hyperactivity-impulsivity persisting for at least 6 months 1
- Cross-situational impairment: Document functional impairment in at least 2 settings (work, home, social relationships) 1
The clinical interview should focus specifically on core ADHD symptoms including inattention, hyperactivity, impulsivity, disorganization, poor time management, and procrastination 2, 3. Adults with ADHD often have poor insight and underestimate symptom severity, making collateral information essential 2.
Validated Rating Scales
Use the Adult ADHD Self-Report Scale (ASRS-V1.1) as your initial screening tool 1:
- Screens positive when the patient endorses "often" or "very often" for 4 or more of 6 questions 1
- Provides systematic symptom quantification 4
Additional validated instruments include 2, 1:
- Wender Utah Rating Scale: Assesses retrospective childhood symptoms 2, 1
- Brown Attention-Deficit Disorder Scale for Adults: Evaluates current adult symptoms 2
- Conners Adult ADHD Rating Scale (CAARS): Comprehensive symptom assessment 2, 5
Collateral Information
Obtain information from a spouse, significant other, parent, or close friend 2, 1. This is critical because adults with ADHD frequently underestimate their symptom severity and resulting impairments 2. The diagnostic process should ideally involve the patient's partner, family, or close relationships 2.
Medical Screening
Physical Examination and Laboratory Testing
Conduct a focused medical assessment to exclude conditions that mimic ADHD 2, 1:
- Cardiovascular screening: Perform careful history, family history of sudden death or ventricular arrhythmia, and physical examination before initiating treatment 6
- Thyroid function tests: Rule out thyroid disorders 1
- Basic metabolic panel: Screen for metabolic conditions 1
- Sleep disorder evaluation: Sleep problems frequently overlap with ADHD symptoms 2
Neurological Conditions
Screen for neurological conditions including head injury sequelae, dementing illnesses, and narcolepsy that can present with attention and impulsivity symptoms 2, 1.
Differential Diagnosis and Comorbidity Assessment
Psychiatric Conditions That Mimic ADHD
Systematically evaluate for conditions that overlap with or commonly co-occur with ADHD 2, 1:
- Bipolar disorder: Can present with impulsivity, distractibility, and mood lability 2, 1
- Major depression: Psychomotor retardation and concentration difficulties overlap with ADHD 2, 1
- Anxiety disorders: Generalized anxiety and social phobia cause concentration problems 2, 1
- Personality disorders: Particularly borderline and antisocial personality disorders 2
- Learning disabilities: May present with academic and occupational difficulties 2
Substance Use Screening
Obtain a detailed history of drug and alcohol use and consider urine drug screening 2. ADHD is associated with high rates of comorbid substance abuse, making this assessment mandatory 2. Document current and past substance use patterns before initiating stimulant medications 4.
Common Psychiatric Comorbidities
ADHD frequently co-occurs with 2:
- Oppositional defiant disorder and conduct disorder 2
- Anxiety disorders (separation anxiety, generalized anxiety, social phobia) 2
- Mood disorders 2
- Sleep problems 2
Diagnostic Algorithm
Follow this step-by-step approach 1:
- Initial screening: Administer ASRS-V1.1 1
- Comprehensive clinical interview: Document childhood onset, current symptoms, and functional impairment 1
- Collateral information: Interview family member or significant other 1
- Structured rating scales: Complete Wender Utah Rating Scale and additional symptom inventories 1
- Comorbidity screening: Systematically evaluate for mood, anxiety, substance use, and personality disorders 1
- Medical screening: Physical examination and laboratory tests to rule out mimicking conditions 1
- Functional impairment assessment: Document impairment in work, relationships, and daily functioning 1
When to Refer to Psychiatry
Consider referral when 1:
- Diagnostic uncertainty persists after comprehensive evaluation 1
- Complex comorbid psychiatric conditions are present 1
- Specialized treatment or polypharmacy is needed 1
- Limited access to ADHD expertise in primary care setting 2
Critical Pitfalls to Avoid
Do not rely on clinical interview alone: Both clinical interviews and ADHD rating scales used in isolation have adequate sensitivity but poor specificity 7. Combining multiple assessment modalities significantly improves diagnostic accuracy 7.
Do not diagnose ADHD based solely on cognitive testing: Cognitive test batteries have inadequate sensitivity and specificity for identifying ADHD 7. While cognitive tests combined with behavior rating scales improve specificity, they should not be used as standalone diagnostic tools 7.
Do not overlook symptom validity: Consider response validity and symptom validity testing, particularly in medicolegal contexts or when secondary gain is suspected, as these tests have good sensitivity and excellent specificity in detecting invalid symptom presentation 7.
Do not miss childhood onset: The diagnosis requires documentation of symptoms before age 12 years 1. Without childhood onset, consider alternative diagnoses such as acquired attention problems from medical conditions, substance use, or other psychiatric disorders 2.