CAARS Rating Scale · Scoring & T-Score Interpretation
The CAARS (Conners' Adult ADHD Rating Scales, 18+) is a widely used norm-referenced adult ADHD rating scale. It produces T-scores versus age/gender norms. T ≥65 clinically significant. Published by MHS.
CAARS T-Score Interpreter
More concerns than typically reported (≈93rd–97th percentile). Clinically significant; warrants further assessment.
T-scores are normed by age and gender (mean = 50, SD = 10). Higher scores indicate more frequent or severe concerns. Interpretive ranges follow the CAARS manual.
| T-score | Interpretation |
|---|---|
| 70+ | Very ElevatedMany more concerns than typically reported (≈98th percentile and above). Strongly warrants comprehensive evaluation. |
| 65–69 | ElevatedMore concerns than typically reported (≈93rd–97th percentile). Clinically significant; warrants further assessment. |
| 60–64 | High AverageSlightly more concerns than typically reported. Worth monitoring in context. |
| 30–59 | Average / Not ElevatedWithin the typical range; few concerns reported relative to age- and gender-matched peers. |
CAARS © C. Keith Conners / Multi-Health Systems (MHS). Available from mhs.com; requires purchase and a trained administrator. Educational reference only — not a diagnostic evaluation.
For reference only — not an assessment, diagnosis, or medical advice. This page provides scoring reference material; interpretation and clinical decisions rest with a qualified clinician.
The CAARS (Conners' Adult ADHD Rating Scales, adults 18+) is one of the most widely used norm-referenced adult ADHD rating scales in clinical practice. It produces T-scores compared against age and gender norms. Administered and interpreted by qualified clinicians.
Assessing a child 6–18? See the Conners 3 Rating Scale guide.
What the CAARS measures
The CAARS (Conners' Adult ADHD Rating Scales) is a norm-referenced ADHD rating scale for adults aged 18 and older, developed by C. Keith Conners (1998, updated 2011) and published by Multi-Health Systems (MHS).
Unlike most tools in this library, the CAARS is commercially copyrighted and requires a license from MHS to administer. It produces T-scores (mean = 50, SD = 10), which compare an individual's responses against age- and gender-matched norms, making it more clinically precise than raw sum scores for adult ADHD assessment.
For adult ADHD screening without a commercial licence, the 6-question ASRS-v1.1 Screener is a validated alternative that NYU states is freely available for clinical and non-clinical use, including commercial use, with attribution. The WURS-61 complements adult ADHD evaluation by establishing childhood onset, a DSM-5-TR requirement.
Subscales
- Inattention/Memory Problems
- Hyperactivity/Restlessness
- Impulsivity/Emotional Lability
- Problems with Self-Concept
- Includes ADHD Index: a sensitive global indicator of ADHD status
How to administer the CAARS
The CAARS is available in Self-Report (CAARS-S) and Observer (CAARS-O) versions, providing a multi-informant picture of adult ADHD symptoms. The CAARS-S is completed by the adult being assessed; the CAARS-O is completed by a close observer — typically a partner, parent, or colleague. Discrepancies between the two forms are common and clinically informative.
Protocols are purchased from MHS, and a licensed clinician administers and interprets the results. The CAARS is commonly paired with the WURS-61 to establish childhood onset.
CAARS scoring and interpretation
Responses are converted to T-scores compared against age- and gender-matched norms (mean = 50, SD = 10). Use the interpreter above to translate a T-score into its interpretive band:
- T ≥ 70 — Very Elevated (2 SD above the mean).
- T 65–69 — Elevated; T ≥ 65 (1.5 SD above the mean) is clinically significant.
- T 60–64 — High Average (borderline elevated).
- T < 60 — Average / Not Elevated.
Interpretive ranges follow the CAARS manual. Because scoring is norm-referenced, a T-score is more clinically meaningful than a raw sum alone.
Psychometric properties
In a German validation with 466 adults with ADHD and 847 healthy controls (896 observer data sets), internal consistency (Cronbach's alpha) ranged from .74 to .95. Test-retest reliability ranged from .85 to .92 for the CAARS-S and from .65 to .85 for the CAARS-O. Sensitivity and specificity were high for all four subscales against DSM-IV diagnosis (Christiansen et al., 2012).
Limitations
- Not a diagnosis. The CAARS quantifies symptom severity relative to norms; a DSM-5-TR diagnosis also needs childhood onset before age 12, symptoms in two or more settings, functional impairment, and clinical judgment.
- Self-report and observer bias. Ratings reflect each informant's perception, and self- and observer reports often disagree.
- Current symptoms only. The CAARS does not establish childhood onset; a retrospective measure such as the WURS-61 is often added.
- Licensed. Protocols must be purchased from MHS.
ADHD Screening Workflows in HiBoop
HiBoop does not offer the CAARS; this page is reference material. For ADHD, HiBoop offers the WURS, SNAP-IV, SWAN and NICHQ Vanderbilt, with automated scoring and tracking over time.
HiBoop does not offer this scale. This page is reference material.This library is an academic and clinical reference. A scale described here is not necessarily offered in HiBoop; each page says whether it is.
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 licence to administer. Clinicians must purchase CAARS protocols from MHS (mhs.com) to use it legally. For adult ADHD screening without a commercial licence, the 6-question ASRS-v1.1 Screener is a validated alternative with 68.7% sensitivity and 99.5% specificity; NYU, which licenses it, states it is freely available for clinical and non-clinical use, including commercial use, with attribution and without modification. The WURS-61 is a retrospective scale for establishing childhood-onset ADHD symptoms in adults; check its copyright holder's terms before use.
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.
Bill this assessment
In the US, the CAARS Rating Scale · Scoring & T-Score Interpretation is usually billed under these CPT codes. Payer rules vary.
Measurement-based care in practice
For clinicians
HiBoop does not offer this scale. For the scales it does offer, HiBoop automates delivery, scoring and longitudinal tracking across your patient panel.
For individuals
This page is a clinical reference, not a diagnostic tool. If you have concerns about your own symptoms, bring this information to a qualified mental health professional.
References
- 1.Conners CK, Erhardt D, Sparrow EP. Conners' Adult ADHD Rating Scales (CAARS): Technical Manual. Multi-Health Systems. 1999.
- 2.Christiansen H, Kis B, Hirsch O, et al. German validation of the Conners Adult ADHD Rating Scales (CAARS) II: reliability, validity, diagnostic sensitivity and specificity. Eur Psychiatry. 2012;27(5):321-328.View source
Last reviewed: May 26, 2026
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