Conners 3 Rating Scale · Scoring & T-Score Interpretation
Criterion-standard ADHD rating scale for children and adolescents ages 6–18. T-score interpreter (T≥65 clinical threshold). Parent, teacher, and self-report forms. Conners (2008), MHS.
Conners 3 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 Conners 3 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. |
Conners 3 © C. Keith Conners / Multi-Health Systems (MHS). Available from mhs.com; requires purchase and a trained administrator. Educational reference only — not a diagnostic evaluation.
The Conners Rating Scales are the criterion standard for ADHD assessment in children and adolescents (ages 6–18). Parent, teacher, and self-report versions measure inattention, hyperactivity/impulsivity, and executive function. A T-score of 65 or above indicates clinical concern. Conners (2008).
Assessing an adult? See the CAARS (Conners Adult ADHD Rating Scale).
Looking for the Conners CPT-3? This page covers the Conners 3 Rating Scale, a questionnaire completed by parents, teachers, and youth. The Conners CPT-3 (Continuous Performance Test) is a separate computerized attention task administered directly to the patient. Both are published by MHS.
What is the Conners Rating Scale?
The Conners Rating Scales, developed by C. Keith Conners and published by Multi-Health Systems (MHS), are the most widely used standardized rating-scale system for assessing ADHD and related behavioural, emotional, and academic problems in children and adolescents. The current edition, the Conners 3rd Edition (Conners 3), published in 2008, provides updated norms and expanded coverage of executive functioning and comorbid conditions.
The Conners 3 includes three parallel forms: a Parent report (about the child, 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). Using multiple informants across settings is a key advantage — under DSM-5-TR, ADHD symptoms must be present in two or more settings.
Conners 3 Content Scales & Forms
The Conners 3 uses a multi-informant approach across parent, teacher, and self-report forms. Each form is available in full-length and short versions. The instrument reports six 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.
Scores are reported as T-scores normed to age and gender (mean = 50, SD = 10). Use the interpreter above to translate a T-score into its interpretive band.
How ADHD Is Diagnosed (DSM-5-TR)
The Conners 3 informs, but does not replace, a diagnostic evaluation. A full ADHD evaluation integrates Conners 3 ratings across parent and teacher forms 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), present in two or more settings, with several symptoms emerging before age 12 and clear evidence of functional impairment.
ADHD Outcome Monitoring in HiBoop
HiBoop sends, scores, and tracks the Conners 3 — alongside the ASRS, Vanderbilt, and broader behavioural-health outcomes — for integrated ADHD and neurodevelopmental monitoring across pediatric, school, and outpatient programs. Scores are charted over time, so response to treatment is visible at a glance without manual entry.
Frequently Asked Questions
What is the Conners Rating Scale?
The Conners Rating Scales are norm-referenced questionnaires used to assess ADHD and related behavioural, emotional, and academic problems in children and adolescents ages 6–18. The current edition, the Conners 3rd Edition (Conners 3, published 2008 by Multi-Health Systems), gathers ratings from parents, teachers, and the youth, and reports T-scores normed by age and gender.
What Conners 3 T-score is clinically significant?
A T-score of 65 or higher (about the 93rd percentile) is considered Elevated and clinically significant, warranting further assessment. A T-score of 70 or higher (about the 98th percentile) is Very Elevated. T-scores of 60–64 are High Average. T-scores are normed to age and gender, with a mean of 50 and a standard deviation of 10.
Can the Conners 3 diagnose ADHD?
No. The Conners 3 cannot diagnose ADHD on its own. A diagnosis requires a full clinical evaluation that integrates rating-scale data with a clinical interview, developmental and medical history, direct observation, and assessment of functional impairment across settings, per DSM-5-TR criteria.
What is the difference between the Conners 3 and the Conners CPT-3?
The Conners 3 is a rating scale completed by parents, teachers, and youth about observed behaviour. The Conners CPT-3 (Continuous Performance Test) is a separate computerized task administered directly to the patient to measure sustained attention and inhibitory control. Both are published by MHS but measure different things and are often used together.
Who can administer and interpret the Conners 3?
The Conners 3 is a licensed instrument purchased from MHS and is intended for use by qualified professionals — typically psychologists, physicians, or other clinicians trained in psychological assessment. Scoring and interpretation should be performed by a trained administrator within an appropriate clinical context.
References
- 1.Conners CK. Conners 3rd Edition (Conners 3) Manual. Multi-Health Systems; 2008.
- 2.Conners CK, Sitarenios G, Parker JD, Epstein JN. Revision and restandardization of the Conners Teacher Rating Scale (CTRS-R): factor structure, reliability, and criterion validity. J Abnorm Child Psychol. 1998;26(4):279–291.View source
- 3.Izzo VA, Donati MA, Novello F, Maschietto D, Primi C. The Conners 3-short forms: Evaluating the adequacy of brief versions to assess ADHD symptoms and related problems. Clin Child Psychol Psychiatry. 2019;24(4):791–808.View source
- 4.Christiansen H, Hirsch O, Drechsler R, et al. German Validation of the Conners 3 Rating Scales for Parents, Teachers, and Children. Z Kinder Jugendpsychiatr Psychother. 2016;44(2):139–147.View source
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Last reviewed: Jun 3, 2026
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