Conners Rating Scale (CAARS & Conners 3) · Scoring & T-Scores

The Conners rating scale is a family of norm-referenced ADHD questionnaires published by Multi-Health Systems (MHS): the Conners 3 for children and adolescents aged 6–18 ^[1], and the CAARS (Conners' Adult ADHD Rating Scales) for adults 18 and older ^[5].

Both report T-scores against age- and gender-matched norms, and on both a T-score of 65 or above indicates clinical concern. Qualified clinicians administer and interpret them.

Looking for the Conners CPT-3? That is a separate computerized attention task done by the child or adolescent. This page covers the questionnaires completed by parents, teachers, youth and adults.

Conners 3 or CAARS?

What does the Conners rating scale measure?

The Conners Rating Scales, developed by C. Keith Conners, are among the most widely used standardized rating-scale systems for assessing ADHD and related behavioural, emotional, and academic problems. The Conners 3, published in 2008, provides updated norms and expanded coverage of executive functioning and comorbid conditions ^[1].

Conners 3 content scales

• Inattention — difficulty sustaining attention, careless errors, disorganization.
• Hyperactivity/Impulsivity — restlessness, difficulty waiting, acting without thinking.
• Learning Problems — academic difficulty in reading, math, or spelling.
• Executive Functioning — trouble starting, planning, and completing tasks.
• Defiance/Aggression — argumentativeness, rule-breaking, or aggressive behaviour.
• Peer Relations (and Family Relations on the self-report) — difficulty with social or family relationships.

CAARS subscales

• Inattention/Memory Problems
• Hyperactivity/Restlessness
• Impulsivity/Emotional Lability
• Problems with Self-Concept
• ADHD Index: a sensitive global indicator of ADHD status

The WURS-61 complements adult ADHD evaluation by establishing childhood onset, a DSM-5-TR requirement the CAARS does not cover. For adult screening without a commercial licence, the 6-question ASRS-v1.1 Screener is a validated alternative that NYU states is freely available, with attribution.

How do you give the Conners 3 and CAARS?

The Conners 3 has three parallel forms: a Parent report (completed by a parent or guardian), a Teacher report (completed by the classroom teacher), and a Self-Report (completed by the youth, ages 8–18). Each comes in full-length and short versions. Using informants across settings matters: under DSM-5-TR, ADHD symptoms must be present in two or more settings.

The CAARS has a Self-Report (CAARS-S), completed by the adult being assessed, and an Observer form (CAARS-O), completed by a partner, parent, or colleague. Discrepancies between the two are common and clinically informative.

Both are purchased from MHS and intended for qualified professionals. During active treatment they are commonly repeated at baseline and then every 4–8 weeks to track response.

How do you score and interpret the Conners 3 and CAARS?

Responses are converted to T-scores normed to age and gender (mean = 50, SD = 10). Use the interpreter above to translate a T-score into its interpretive band:

• T ≥ 70 — Very Elevated (about the 98th percentile and above; 2 SD above the mean).
• T 65–69 — Elevated (about the 93rd–97th percentile); clinically significant, warranting further assessment.
• T 60–64 — High Average (borderline elevated).
• T < 60 — Average / Not Elevated.

Interpretive ranges follow the Conners 3 and CAARS manuals. Because scoring is norm-referenced, a T-score is more clinically meaningful than a raw sum alone.

How ADHD Is Diagnosed (DSM-5-TR)

The Conners scales inform, but do not replace, a diagnostic evaluation. A full ADHD evaluation integrates ratings across informants with a clinical interview, developmental history, medical evaluation, and direct observation.

Under DSM-5-TR, a diagnosis requires:

• at least six inattention symptoms or six hyperactivity/impulsivity symptoms (five or more per domain for individuals aged 17 and older)
• symptoms present in two or more settings
• several symptoms emerging before age 12
• clear evidence of functional impairment

Psychometric properties

Conners 3. Hardly any peer-reviewed studies report Conners 3 psychometrics beyond the test manual itself ^[4]. The published studies:

• German validation (745 children, 953 parents, 741 teachers; ages 6–18). Confirmatory factor analyses showed very good model fit with highly satisfying internal consistency (Cronbach's α), although exploratory factor structures differed from the American model ^[4].
• Italian short forms (591 youth, 631 parent and 325 teacher ratings). The short forms reproduced the original multidimensional structure and were reliable and valid for assessing ADHD and its main comorbid conditions ^[3].
• Predecessor (CTRS-R). The revised teacher scale correctly classified 85% of children with ADHD versus typically developing children, with generally satisfactory test-retest and internal-consistency reliability ^[2].

CAARS. 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 ^[6].

Limitations

• Not a diagnosis. Both quantify symptom severity relative to norms; a diagnosis needs a full clinical evaluation.
• Rater perspective. Parent, teacher, self- and observer ratings reflect each informant's view and often disagree; ratings from one setting cannot establish the cross-setting requirement on their own.
• Current symptoms only (CAARS). The CAARS does not establish childhood onset; a retrospective measure such as the WURS-61 is often added.
• Norm dependence. T-scores compare a person with the normative sample; cross-cultural use needs local validation, and factor structures have differed in translated versions ^[4].
• Licensed. Forms and manuals are purchased from MHS and require a trained administrator.