What are the recommended Adult Attention Deficit Hyperactivity Disorder (ADHD) scales for collateral informants to assess symptoms in adults with ADHD?

Recommended Adult ADHD Scales for Collateral Informants

For collateral informant assessment of adult ADHD, use the Conners' Adult ADHD Rating Scale-Observer Report (CAARS-O) as your primary tool, supplemented by having the informant complete the Adult ADHD Self-Report Scale (ASRS) with the patient in mind. 1

Primary Recommended Scales

Conners' Adult ADHD Rating Scale (CAARS) - Observer/Informant Version

• This is the most widely validated and recommended collateral informant scale for adult ADHD assessment 1, 2, 3
• Provides structured assessment across multiple symptom domains with established psychometric properties 3, 4
• Demonstrates significant correlation with objective measures of ADHD impairment, contributing 16.4% of variance in cognitive testing discrepancies 5
• Shows higher intercorrelations between same scales across different formats (self vs. observer), particularly for externally visible symptoms 5

Adult ADHD Self-Report Scale (ASRS) - Completed by Informant

• Have someone who knows the patient well (spouse, parent, close friend) complete the ASRS with the patient in mind to gain insights into how symptoms are perceived by and impact those around them 1, 2
• This approach provides comparative perspective when used alongside patient self-report 1
• Particularly useful for identifying functional impairments that patients may underestimate 2

Additional Validated Options

Wender Parent's Rating Scale

• Specifically designed to gather retrospective childhood symptom information from parents 1, 2
• Critical for establishing symptom onset before age 12, which is a diagnostic requirement 2
• Particularly valuable when assessing adults whose parents can provide historical context 1, 6

Brown Attention-Deficit Disorder Scale for Adults

• Can be administered to collateral informants 1, 2
• Demonstrated strong predictive validity for clinical diagnosis in research studies 3
• Useful for comprehensive symptom assessment beyond DSM criteria 4

Critical Clinical Rationale

Why Collateral Information is Essential

Adults with ADHD are notoriously poor self-reporters and often underestimate the severity of their symptoms and resulting impairments 1, 2. This creates a fundamental assessment challenge that necessitates collateral input:

• Self-report alone is insufficient - while adults with ADHD may be the best informants regarding their symptoms, they consistently tend to underreport symptom severity 3
• Informant reports provide additional information on symptoms and impairment that patients may not recognize or acknowledge 3
• Multi-informant assessment yields richer understanding of context-specific symptom displays across different settings (home, work, social) 1

Complementary Nature of Multiple Informants

• Neither self-report nor informant-report formats demonstrate superior accuracy when used alone 5
• Both self and informant ratings contribute significant but different information in relation to external validation criteria 7
• Self-ratings may correlate more strongly with subjective impairment, while other-ratings may better reflect observable executive function deficits 7
• The multi-informant approach demonstrates construct validity specifically for adult ADHD assessment 1

Practical Implementation Algorithm

1. Initial screening: Have patient complete ASRS Part A 1, 2

2. If screen positive: Obtain collateral information using:

   • Primary: CAARS-Observer Report from spouse/partner or close family member 1, 3, 4
   • Secondary: Have same informant complete ASRS with patient in mind 1
   • Historical: Wender Parent's Rating Scale from parents (if available) for childhood symptom verification 1, 6

3. Compare reports: Look for convergence and divergence between self and informant ratings, particularly for:

   • Externally visible symptoms (hyperactivity, impulsivity) where agreement is typically higher 5
   • Functional impairments in daily activities that patients may minimize 1, 2
   • Cross-setting symptom displays required for diagnosis 2, 6

Common Pitfalls to Avoid

• Do not rely solely on patient self-report - this violates diagnostic requirements for cross-setting symptom verification and ignores patients' tendency to underestimate impairment 1, 2, 6
• Avoid using only unstructured collateral interviews - validated rating scales provide standardized, psychometrically sound assessment 3, 4
• Do not dismiss informant-patient discrepancies - these may reflect genuine context-specific symptom variation or differential awareness of impairment 5, 7
• Remember that DSM-IV symptom factors developed for children achieve lower patient-informant agreement than other validated adult-specific measures 3