Conners Adult ADHD Rating Scales 2nd Edition Now Available!

Conners Adult ADHD Rating Scales 2nd Edition Now Available!

MHS is proud and excited to announce the upcoming release of the Conners Adult ADHD Rating Scales 2nd Edition (CAARS™ 2), a measure that provides improved accuracy, greater insight, and enhanced utility for assessing and managing Attention-Deficit/Hyperactivity Disorder (ADHD) in adults. The Conners Adult ADHD Rating Scales (CAARS™; Conners, Erhardt, & Sparrow, 1999), first published more than 20 years ago, has played a crucial role in ADHD assessments in adults for over two decades.

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Why did MHS revise CAARS?

The CAARS has been a trusted resource; however, over the last two decades, our understanding of ADHD has grown, and research has shed light on new aspects of the disorder. These developments necessitated a revision to ensure the measure remained relevant and effective. The CAARS 2 aims to improve the accuracy of ADHD diagnosis, ultimately leading to more appropriate treatment, monitoring, and support for individuals.

With the goals of updating the normative samples, expanding the coverage of ADHD-related content, and meeting standards of fairness and cultural sensitivity, MHS worked closely with authors C. Keith Conners, Ph.D.i, Drew Erhardt, Ph.D., and Elizabeth Sparrow, Ph.D., to develop the CAARS 2. The CAARS 2 is a versatile measure, offering different versions to suit users’ individual needs, including the CAARS 2 (full-length) for initial evaluations or periodic re-assessments, the CAARS 2–Short for repeated assessments, and the CAARS 2–ADHD Index that can be used for very brief assessments (e.g., frequent treatment monitoring or gathering research data).

Join us as we delve into the significance of this revision and its impact on the assessment and understanding of ADHD in adults.

What’s New in the CAARS 2?


New normative data were derived from a large sample selected to be representative of the North American population based on the 2018 U.S. census and the 2016 Canadian census proportions (balanced equally by age and stratified by gender, race/ethnicity, education level, and geographic region). An ADHD Reference Sample has been added to allow examiners to compare an individual’s scores to those produced by others already diagnosed with ADHD.


The oldest normative sample age group in the original CAARS was 50 years and older. The CAARS 2 Normative Sample includes stratified samples for seven age groups, with an upward expansion to include 50–59, 60–69, and 70+ years to ensure precision when assessing older adults.


Increased fairness and inclusivity with gender-inclusive language, culturally sensitive items, and items and scales that show no evidence of measurement bias with respect to gender, race/ethnicity, country of residence, or education level.


In addition to English, the CAARS 2 forms are available in Spanish (North America) and French (Canada). These versions are linguistically and culturally sensitive adaptations of the English forms.


  • A new, comprehensive Response Style Analysis section has been added to improve the ability to detect problematic response styles, including enhanced validity scales to capture invalid responding.
  • There is the addition of research-based item-level indicators to screen for issues that may require clinical follow-up (suicidality, self-harm, anxiety, depression).
  • In addition to retaining the best-performing items from the original CAARS, dozens of new rationally derived and empirically evaluated items were added to the Content Scales, and the scale structure has been updated.
  • The DSM Symptom Scales have been updated and aligned with current DSM symptom criteria.
  • The updated CAARS 2‒ADHD Index, derived from advanced statistical techniques, aims to optimize its accuracy in discriminating between individuals with and without ADHD.
  • Items were also created to assess impairment and functional outcomes typically experienced by individuals with ADHD symptoms.


Examiners can now select reference samples from the General Population or individuals with ADHD. Both reference samples include the option to compare against a Combined Gender group, a Gender Specific–Males group, and a Gender Specific–Females group. The report allows a convenient side-by-side comparison of rater scores with multiple groups.


The CAARS 2 and Conners 4 (a measure of symptoms of and impairments associated with ADHD, along with common co-occurring problems and disorders for youth aged 6 to 18 years) were designed to be aligned and comparable to one another to facilitate a lifespan approach to ADHD assessment and monitoring and to simplify the integration of information as adolescents transition into adulthood.


Each CAARS 2 purchase on the MHS Online Assessment Center+ (MAC+) can be used to generate reports for any of the CAARS 2 forms (Self-Report or Observer forms of the full-length CAARS 2, CAARS 2–Short, or CAARS 2–ADHD Index) in any available language. This flexibility eliminates the need to monitor remaining balances for different forms. Reports can be generated multiple times at no additional charge. If you prefer paper administration, you can still print the assessment form. The responses can then be entered into the MHS Online Assessment Center+ for online scoring and report generation.

The release of the Conners Adult ADHD Rating Scales 2nd Edition (CAARS™ 2) represents a significant milestone in the field of mental health assessment. It reflects the ongoing commitment to advancing our understanding of ADHD in adults and ensuring that individuals ultimately receive the most accurate diagnoses and appropriate support. We are confident that the CAARS 2 is a tool that will facilitate the accurate, comprehensive, multi-method, and multi-informant assessment of ADHD in adults for years to come.

Have questions? Get in touch with a member of our team today.


i Dr. Conners passed away during the development phase of the CAARS 2; however, we were fortunate to have Dr. Conners contribute to the conceptualization of the revision, and we are pleased that the final product reflects his vision.

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