CAARS Scoring & Interpretation — Conners Adult ADHD Rating Scales (T-Score Guide)
Conners 3 (ages 6–18) and CAARS (adults 18+) are the most widely used norm-referenced ADHD rating scales. Both produce T-scores versus age/gender norms. T ≥65 clinically significant. Published by MHS.
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.
References
- 1.Conners CK, Erhardt D, Sparrow EP. Conners' Adult ADHD Rating Scales (CAARS): Technical Manual. Multi-Health Systems. 1999.
Frequently Asked Questions
What is the CAARS?
The CAARS (Conners' Adult ADHD Rating Scales) is a norm-referenced ADHD rating scale for adults aged 18 and older, published by Multi-Health Systems (MHS). Developed by C. Keith Conners in 1998 (updated 2011), the CAARS produces T-scores compared against age- and gender-matched norms (mean = 50, SD = 10). T-scores at or above 65 (1.5 SD above the mean) are considered clinically significant. The CAARS is available in self-report and observer-report forms. It requires a licensed clinician to administer and interpret.
What CAARS T-score is clinically significant?
A CAARS T-score at or above 65 is clinically significant, indicating ADHD symptoms that are 1.5 standard deviations above the population mean for the respondent's age and gender. T-scores of 60–64 are considered borderline elevated. T-scores of 70 or above indicate very clinically elevated symptoms, 2 standard deviations above the mean. T-scores below 60 are within normal limits. Because the CAARS uses norm-referenced scoring, a T-score of 65+ is more clinically meaningful than a raw sum cutoff alone.
How does the CAARS differ from the Conners 3?
The CAARS and Conners 3 are complementary scales published by MHS. The CAARS is designed for adults (18+) with both self-report and observer forms. The Conners 3 is designed for children and adolescents ages 6–18, with parallel Parent, Teacher, and Self-Report forms. Both produce T-scores compared to age- and gender-matched norms and identify the same ADHD symptom domains (inattention, hyperactivity/impulsivity, DSM symptom criteria). Clinicians assessing adult ADHD with suspected childhood onset sometimes use the WURS-61 alongside the CAARS to establish retrospective childhood symptoms.
Is the CAARS free to use?
No. The CAARS is commercially copyrighted by Multi-Health Systems (MHS) and requires a paid license to administer. Clinicians must purchase CAARS protocols from MHS (mhs.com) to use it legally. For adult ADHD screening without a commercial license, the ASRS-v1.1 (Adult ADHD Self-Report Scale) is a free validated alternative with 68.7% sensitivity and 99.5% specificity. The WURS-61 is a free retrospective scale for establishing childhood-onset ADHD symptoms in adults.
Can the CAARS diagnose ADHD?
No. The CAARS is a rating scale that quantifies ADHD symptom severity relative to age and gender norms — it does not diagnose ADHD. A DSM-5-TR diagnosis of ADHD requires: symptoms in two or more settings, onset before age 12, significant functional impairment, and clinical judgment that symptoms are not better explained by another condition. The CAARS provides standardized symptom data that supports but does not replace a full clinical evaluation, developmental history, and multi-informant assessment.
What is the difference between CAARS-S and CAARS-O?
The CAARS-S (Self-Report) is completed by the adult being assessed, rating their own ADHD symptoms. The CAARS-O (Observer Report) is completed by a close observer — typically a partner, parent, or colleague — who rates the adult's ADHD behaviours as they observe them. Using both forms together provides a multi-informant picture of symptom severity and identifies discrepancies between self-perception and observed behaviour. Discrepancies between CAARS-S and CAARS-O are clinically informative and common in adult ADHD assessment.
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