In this article, we explain everything you need to know about the Conners’ Rating Scales. We will cover the aspects it evaluates, the target population, a detailed step-by-step explanation, and how to interpret its results. Additionally, we will dive into the scientific evidence supporting this tool (diagnostic sensitivity and specificity) in clinical assessment. You will also find official and unofficial sources available for download in PDF format.
Conners Rating Scales
score interpreter & screening assistant
Convert and interpret T-scores from the Conners 4, Conners 3, Conners CBRS, Conners EC and CAARS 2; compare raters across settings; and run a free, unlicensed DSM-5-TR ADHD symptom count when you don't have access to a published Conners form.
Conners T-scores are normed to a mean of 50 and a standard deviation of 10 for the selected age, gender and reference sample. Higher scores mean the rater reported more concerns than are typical for that comparison group.
- T-score
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- Percentile
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- z-score
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- Conf. interval
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Φ is the standard normal cumulative distribution. Conners 4 and CAARS 2 reports print empirical percentiles taken from the observed reference-sample distribution, so the normal-curve percentile above is an approximation and can differ by a few points from the figure printed on your report. Where the two disagree, the printed report wins.
This converts a raw score to a linear T-score. The normative mean and SD are safety-critical: they are never assumed, guessed or defaulted here. Read them from the norm table in your own manual, for this exact scale, form, rater, age group and reference sample.
- Raw
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- z-score
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- Percentile (approx.)
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- Back-check raw
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Conners 4 and CAARS 2 use continuous norming, and their reports print empirical percentiles rather than normal-curve percentiles. A linear T computed from a published M and SD is therefore an estimate. Use it to check or understand a report — never to replace one.
The error this tool exists to prevent
A raw score means nothing on its own. Below is your raw score converted under two different norm tables. Same behaviour, same questionnaire, opposite conclusions.
DSM-5-TR requires that symptoms be present in two or more settings. Conners scales are built for multi-informant use, so enter the same scale's T-score from each rater you have. Disagreement between raters is normal and informative — it is not evidence that someone is wrong.
Inter-rater agreement on ADHD rating scales is modest by design: raters see different settings and different demands. In the CAARS 2 standardisation, self-report and observer ratings correlated at a median r of roughly .44 to .54, while the same rater repeating the scale correlated far more strongly. A parent–teacher gap is therefore expected and is data about context, not noise to be averaged away.
A single elevated rater does not establish cross-setting impairment. Two elevated raters do not establish a diagnosis. Both are prompts for history, observation and differential diagnosis.
The Conners forms are copyrighted and sold by Multi-Health Systems; there is no legitimate free PDF of them. This is not a Conners scale and produces no T-score. It is an independently worded, 18-item count of the DSM-5-TR ADHD symptom criteria, using the response set and symptom threshold shared by the freely available NICHQ Vanderbilt scales: a symptom is counted when it is rated Often or Very often.
Response set: 0 Never / rarely · 1 Occasionally · 2 Often · 3 Very often. Ratings of 2 or 3 count as a present symptom. Item wording is written for this tool and is not reproduced from any published questionnaire.
| Instrument | Ages | Raters | Length | Focus |
|---|---|---|---|---|
| Conners 4 (2022) | 6–18 self-report 8–18 | Parent, teacher, self | 109–118 items Short 49–53; ADHD Index 12 | ADHD symptoms, impairment and functional outcomes, common co-occurring concerns |
| Conners 3 (2008) | 6–18 | Parent, teacher, self | Full, short and index forms | ADHD and closely associated problems; superseded by Conners 4 |
| Conners CBRS | 6–18 | Parent, teacher, self | Full-length | Broad behavioural, emotional, academic and social concerns |
| Conners EC (2009) | 2–6 | Parent, childcare provider | Full and short | Behaviour and developmental milestones in early childhood |
| CAARS 2 (2023) | 18+ | Self, observer | 10–20 min Short 5–10; ADHD Index 1–3 | Adult ADHD symptoms, impairment, response style, screening items |
| CAARS (1999) | 18+ | Self, observer | Long, short, screening | Original adult scale; superseded by CAARS 2 |
| Conners CPT 3 / K-CPT 2 | 8+ / 4–7 | Performance task | 14 min | A computerised attention task — not a rating scale, and scored differently |
MHS specifies that the Conners 4 must not be used outside its age range because the normative data do not apply beyond the ages studied. For a 6-year-old in kindergarten MHS recommends the Conners EC; for a 6-year-old in Grade 1, the Conners 4. For an 18-year-old still in high school, the Conners 4; for an 18-year-old who has left, the adult scale.
| T-score | Percentile | Conners 4 / CAARS 2 label | Conners 3 / CBRS label | Meaning |
|---|---|---|---|---|
| ≥ 70 | ≥ 98 | Very Elevated | Very Elevated | Many more concerns than are typically reported |
| 65–69 | 93–97 | Elevated | Elevated | More concerns than are typically reported |
| 60–64 | 84–92 | Slightly Elevated | High Average | Slightly more concerns than are typically reported |
| 40–59 | 16–83 | Average | Average | Typical levels of concern |
| < 40 | < 16 | Low | Low | Fewer concerns than are typically reported |
Bands are approximations, not rules. The Conners 4 manual notes explicitly that a T-score of 69 and one of 70 fall in different categories although they do not differ meaningfully, and that the 60–64 band is a borderline zone requiring clinical judgement and consideration of the confidence interval. Conners 4 scores are floored at T = 10 and capped at T = 100.
| Criterion | Requirement |
|---|---|
| Symptom count | ≥ 6 of 9 in a domain (age ≤ 16) · ≥ 5 of 9 (age ≥ 17) |
| Duration | Persisting at least 6 months, to a degree inconsistent with developmental level |
| Age of onset | Several symptoms present before age 12 |
| Settings | Present in ≥ 2 settings |
| Impairment | Clear evidence symptoms interfere with or reduce quality of functioning |
| Exclusion | Not better explained by another mental disorder, and not exclusively during psychosis |
| Presentation | Predominantly inattentive · predominantly hyperactive-impulsive · combined |
Every Conners instrument is a copyrighted, restricted-use test published by Multi-Health Systems. Forms are sold, administration requires user qualification, and scoring uses norm tables that are not published free of charge. Copies circulating as free PDFs are unauthorised, are frequently the obsolete 1997 revision (CRS-R) or a fragment of it, and cannot be scored against current norms. Using an outdated form with modern band labels produces a number that looks authoritative and means nothing.
If you need a validated instrument at no cost, the NICHQ Vanderbilt Assessment Scales (parent and teacher, ages 6–12) are distributed freely by the American Academy of Pediatrics and NICHQ, and the WHO Adult ADHD Self-Report Scale (ASRS v1.1) is freely available for adults. Neither yields a Conners T-score, and neither diagnoses ADHD.
- Conners, C. K. Conners 4th Edition Manual (online edition). Multi-Health Systems — chapters on forms, age ranges, and Conners 4 scores (Table 4.1, T-score and percentile guidelines; score capping; confidence intervals). manual chapter 4
- Multi-Health Systems. Conners 3rd Edition Supplement (Table 2, T-score and percentile guidelines; revised validity-scale language). C3 supplement (PDF)
- Multi-Health Systems. Conners CBRS Supplement (Table 2, T-score and percentile guidelines; DSM symptom-count interpretation).
- Multi-Health Systems. CAARS 2 — Conners Adult ADHD Rating Scales, 2nd Edition: age range, forms, administration times, normative sample structure and reliability figures. CAARS 2 product documentation
- American Academy of Pediatrics / NICHQ. NICHQ Vanderbilt Assessment Scales and Scoring Instructions (symptom items 1–9 and 10–18; a rating of 2 or 3 counts as a positive response; performance items). scoring instructions (PDF)
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th ed., text revision (DSM-5-TR), 2022 — ADHD criteria A–E and presentation specifiers.
- National Institute for Health and Care Excellence. Attention deficit hyperactivity disorder: diagnosis and management (NG87) — rating scales support but never establish a diagnosis. NICE NG87
Nothing in this tool is investigational. It implements no proprietary Conners item, weighting or norm table; it applies published, publicly documented interpretation bands to a number you supply.
Full disclaimer, limitations and how to report an error (expand)
What this tool is
An educational reference and decision aid for people who already have a Conners report, a Conners manual, or a clinical question about ADHD rating scales. It performs arithmetic on values you enter and displays published interpretation guidelines alongside them.
What it is not
- It is not the Conners Rating Scales. It contains no Conners items, no Conners norm tables and no Conners scoring algorithm. Those are copyrighted material of Multi-Health Systems and are available only through MHS and its authorised distributors.
- It is not a diagnostic instrument. ADHD is diagnosed clinically. NICE guideline NG87 and the Conners manuals are explicit that a rating scale supports assessment and never establishes a diagnosis on its own.
- It does not give clinical recommendations. It will not tell you whether to treat, refer, medicate or re-test.
- It is not affiliated with, endorsed by, or connected to Multi-Health Systems, C. Keith Conners, NICHQ, the American Academy of Pediatrics, or the American Psychiatric Association. All trademarks belong to their owners.
Known limitations
- Percentiles shown here are derived from the standard normal curve. Conners 4 and CAARS 2 reports print empirical percentiles from the observed reference sample, which can differ. The printed report is authoritative.
- The raw-to-T converter applies a linear transformation. Current Conners instruments use continuous norming, so a linear T is an approximation, useful for checking and teaching, not for reporting.
- Confidence intervals are computed from a reliability coefficient you supply, using the scale's standard error of measurement. Conners manuals publish per-scale, per-form confidence intervals in their appendices; use those in a report.
- Interpretation bands assume the standard general-population reference sample. If your report used an ADHD reference sample or a gender-specific sample, the same T-score carries a different meaning.
- The symptom count in tab 04 is a criterion checklist, not a norm-referenced measure. It has no T-score, no validity scales and no published sensitivity or specificity as implemented here.
Safety
If you or someone you are rating is having thoughts of self-harm or suicide, stop using this tool and seek help immediately from a local emergency number or crisis service. ADHD rating scales are not designed to detect risk.
Reporting an error
If you believe a figure, band, threshold or citation on this page is wrong, please report it through the contact page of clinicaltoolslibrary.com so it can be corrected and re-reviewed. Adverse events or safety concerns relating to a medical product should be reported to your national regulator — in the United States via the FDA MedWatch programme (fda.gov/safety/medwatch), in the United Kingdom via the MHRA Yellow Card scheme, and in the EU via your national competent authority or EMA.
Privacy
All calculation happens in your browser. Nothing you type is transmitted anywhere. This tool stores only your display preferences (theme, audience mode and last-selected instrument) in your browser's local storage. No score, age, name or clinical value is ever stored.
What does the Conners’ Rating Scales assess?
The Conners’ Rating Scales are standardized assessment tools designed to evaluate behavioral symptoms associated with Attention-Deficit/Hyperactivity Disorder (ADHD) and related disruptive behavior disorders in children and adolescents. These scales provide structured input from parents, teachers, and clinicians to measure symptom severity across domains such as inattention, hyperactivity, and impulsivity. The main purpose of the Conners’ Rating Scales is to facilitate accurate identification and monitoring of behavioral problems, supporting diagnostic and treatment planning processes. Clinicians often refer to resources like the Conners Rating Scale pdf scoring or the Conners Parent Rating Scale manual for standardized administration and interpretation guidelines. The scales include specific scoring sheets and manuals, such as the conners’ rating scale manual pdf, to ensure consistent application and reliable clinical outcomes.
For which type of patients or populations is the Conners’ Rating Scales intended?
The Conners’ Rating Scales are primarily indicated for pediatric patients aged 6 to 18 years suspected of exhibiting symptoms consistent with Attention-Deficit/Hyperactivity Disorder (ADHD) and related behavioral disorders. These scales are most useful in clinical settings such as child psychiatry, psychology, and developmental pediatrics to obtain multi-informant assessments from parents, teachers, and clinicians. Utilization of standardized tools like the Conners Parent Rating Scale manual enhances diagnostic accuracy by providing objective measures of symptom severity and behavioral patterns. Furthermore, the scales facilitate monitoring treatment response and guiding intervention strategies through systematic scoring and interpretation, often referenced in resources like the Conners Rating Scale pdf scoring guidelines. Their application is critical when differential diagnosis is necessary to distinguish ADHD from other neurodevelopmental or emotional disorders in complex clinical presentations.
Step-by-Step Explanation of the Conners’ Rating Scales
The administration of the Conners’ Rating Scales begins with selecting the appropriate form, typically comprising 27 to 80 items, depending on the version (Short Form or Comprehensive). Each item assesses behaviors related to Attention-Deficit/Hyperactivity Disorder (ADHD) and related disorders, utilizing both symptom frequency and severity questions. Respondents, often parents or teachers, rate each behavior on a 4-point Likert scale ranging from “Not at all” (0) to “Very much” (3). The clinician ensures clarity by providing standardized instructions emphasizing the observation period, usually the past month. Upon completion, scores are tallied according to the scale’s diagnostic algorithms to identify symptom clusters in domains such as inattention, hyperactivity, and impulsivity, facilitating an objective assessment of behavioral concerns in children and adolescents.
Download Conners’ Rating Scales PDF | Original & English Versions with Scoring Sheets for ADHD
Professionals and caregivers will find downloadable resources for the Conners’ Rating Scales available below, including both the original and English versions in PDF format. These materials encompass the Conners Rating Scale pdf free download, as well as the Conners Rating Scale scoring sheet, designed to facilitate accurate assessment and interpretation. Such documents are essential tools for evaluating conditions related to ADHD and other behavioral disorders, ensuring standardized and reliable measurement across diverse populations.
How to interpret the results of the Conners’ Rating Scales?
Interpretation of the Conners’ Rating Scales involves comparing raw scores against standardized reference values, typically represented as T-scores with a mean of 50 and a standard deviation of 10. Scores above 65 suggest clinically significant symptoms related to Attention-Deficit/Hyperactivity Disorder (ADHD) or other behavioral concerns. The formula for converting raw scores to T-scores is T = 50 + 10 × ((X – M) / SD), where X is the individual’s raw score, M is the mean of the normative sample, and SD is the standard deviation. For healthcare professionals, elevated T-scores indicate the need for further comprehensive evaluation and may guide diagnostic decisions, treatment planning, and monitoring of symptom progression or response to interventions.
What scientific evidence supports the Conners’ Rating Scales ?
The Conners’ Rating Scales, originally developed in the 1960s by Dr. C. Keith Conners, have undergone extensive validation to assess behavioral concerns primarily associated with Attention-Deficit/Hyperactivity Disorder (ADHD). The scales have demonstrated strong psychometric properties, including high internal consistency and test-retest reliability across diverse populations. Numerous studies have confirmed the tool’s criterion validity through comparisons with clinical diagnoses and other standardized assessments. Normative data were established from large, representative samples, enabling accurate differentiation between typical and atypical behaviors. Additionally, factor analyses have consistently supported the underlying constructs measured by the scales, such as inattention and hyperactivity/impulsivity, solidifying their utility in both clinical and research settings.
Diagnostic Accuracy: Sensitivity and Specificity of the Conners’ Rating Scales
The Conners’ Rating Scales demonstrate a sensitivity ranging from approximately 70% to 90% in identifying symptoms associated with Attention-Deficit/Hyperactivity Disorder (ADHD), depending on the specific version and population studied. Their specificity is generally reported between 80% and 95%, indicating a strong ability to correctly exclude individuals without the disorder. Variability in these metrics is influenced by factors such as the informant source (parent, teacher, or self-report) and the clinical setting. Overall, the scales offer robust psychometric properties that support their use as reliable screening tools in both research and clinical practice.
Related Scales or Questionnaires
The Conners’ Rating Scales are frequently compared to other established instruments such as the Vanderbilt Assessment Scales, the Swanson, Nolan, and Pelham IV (SNAP-IV) Rating Scale, and the Child Behavior Checklist (CBCL), each of which is thoroughly detailed on ClinicalToolsLibrary.com. The Vanderbilt scales offer comprehensive evaluation of ADHD symptoms and comorbid conditions but may require more time to administer compared to Conners. The SNAP-IV, notable for its brevity and focus on core ADHD criteria, provides ease of use but may lack the depth for broader behavioral assessment. The CBCL covers a wide range of emotional and behavioral problems but is less specific to attention disorders. All these tools, including the Conners Rating Scale versions such as the Conners Parent Rating Scale manual and the Conners ADHD Rating Scale PDF for adults, are available for review and download. While Conners scales benefit from extensive normative data and validated scoring sheets, clinicians should consider the varying administration time and target age groups when selecting the most appropriate instrument.
