Conners / CAARS: ADHD Rating Scales

The Conners 3 (ages 6–18) and CAARS (adults 18+) are the most widely used norm-referenced ADHD rating scales in clinical practice. Both produce T-scores compared against age and gender norms. Administered and interpreted by qualified clinicians.

What are the Conners Scales?

The Conners scales are norm-referenced ADHD rating scales developed by C. Keith Conners, originally introduced in 1969 and extensively revised. The current editions are published by Multi-Health Systems (MHS). The Conners 3 (Third Edition, 2008) covers children and adolescents aged 6–18, with parallel Parent, Teacher, and Self-Report forms. The CAARS (Conners' Adult ADHD Rating Scales, 1998, updated 2011) covers adults 18 and older.

Unlike most tools in this library, the Conners scales are commercially copyrighted and require a license from MHS to administer. They produce T-scores (mean = 50, SD = 10), which compare an individual's responses against age- and gender-matched norms, making them more clinically precise than raw sum scores for ADHD assessment.

For ADHD screening without a commercial license, the ASRS-v1.1 (adult) and NICHQ Vanderbilt (children) are free validated alternatives. The WURS-61 complements adult ADHD evaluation by establishing childhood onset, a DSM-5-TR requirement.

Conners T-Score Interpreter

Enter a T-score from a Conners 3 or CAARS report to see the corresponding clinical interpretation.

T-scores require a licensed MHS assessment. This interpreter is for educational reference only.

T-Score Bands

Standard T-score interpretation for Conners 3 and CAARS. T = 50 is exactly average for the norm group.

Conners 3 vs CAARS, Which to Use?

The choice between Conners 3 and CAARS depends on the patient's age and the assessment context.

Children & Adolescents

• Parent, Teacher, and Self-Report forms
• Screens Inattention, Hyperactivity/Impulsivity, Executive Functioning, Learning Problems, Peer Relations, Aggression
• Includes validity index to detect inconsistent responding
• DSM-5-TR symptom subscales aligned to ADHD criteria
• Self-Report (CAARS-S) and Observer (CAARS-O) versions
• Subscales: Inattention/Memory Problems, Hyperactivity/Restlessness, Impulsivity/Emotional Lability, Problems with Self-Concept
• Includes ADHD Index: sensitive global indicator of ADHD status
• Commonly paired with WURS-61 to establish childhood onset

Free ADHD Screening Alternatives

When a licensed Conners assessment is not available, validated free alternatives cover most clinical screening needs.

Adult ADHD Self-Report Scale

18-item World Health Organization-endorsed adult ADHD screener. Part A (6 items) is the validated quick screen. Free for clinical use.

NICHQ Vanderbilt

Pediatric ADHD Rating Scale

AAP-endorsed parent and teacher forms for ADHD evaluation in children ages 6–12. Free for clinical use.

Wender Utah Rating Scale

Retrospective childhood ADHD screener for adults. Establishes the early onset required for DSM-5-TR diagnosis. Free for clinical use.

ADHD Screening Workflows in HiBoop

ASRS, WURS-61, and NICHQ Vanderbilt, automated scoring and multi-rater comparison for complete ADHD evaluation.