Now available! The new Conners Adult ADHD Rating Scales 2nd Edition (CAARS 2) builds upon the strong foundation provided by its predecessor to deliver improved accuracy, greater insight, and enhanced utility for assessing and managing Attention-Deficit/Hyperactivity Disorder (ADHD) in adults.
Adults aged 18 years and over.
The CAARS 2 is an even more comprehensive tool that, in conjunction with other sources of information, aids in the diagnostic process, treatment evaluation, and monitoring. This new edition provides updated, expanded, and reconceptualised scales and new scales to cover core symptoms of ADHD and its associated clinical concerns in adults 18 years and older.
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).
Find out how CAARS 2 compares to CAARS in this comparison sheet.
All CAARS 2 users receive access to a free, digital version of the CAARS 2 Manual through their MHS Online Assessment Center+ account.
Increased fairness and inclusivity
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.
Multiple reference samples
Test users 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.
Increased alignment with Conners 4th Edition
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 children and young people 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.
Forms and manual accessed via the MHS Online Assessment Center+
Please note that the CAARS 2 is administered via publisher Multi-Health Systems’ MHS Online Assessment Center+. Following payment, account set-up usually takes 1-2 business days. If you have any questions about the process or platform, please contact us.
Qualification level required:
Level 2. Please see our Test User Qualifications page for guidance.
The CAARS 2 Self-Report and Observer scale scores have excellent internal consistency (median omega coefficient = .94 for Self-Report and .95 for Observer), strong test-retest reliability (median r = .92 for Self Report and .84 for Observer), and moderate inter-rater reliability (median r = .44 to .54, depending on nature of the relationship), which is expected given the different perspectives from multiple raters. Standard error of measurement (SEM) is low for all CAARS 2 T-scores (median SEM = 2.52 for Self-Report and 2.27 for Observer), indicating very little error in the estimated true scores and high precision. Similarly strong evidence of reliability was found for the CAARS 2–Short and CAARS 2–ADHD Index.
Results from confirmatory factor analyses (CFA) provided evidence to support the internal structure of the CAARS 2 scales (5-factor model fit best; CFI = .943, RMSEA = .047, loadings > .400). Evidence for the relationship to other measures supported the convergence of constructs (median correlations with measures of ADHD and impairment ranged from .48 to .83). The CAARS 2 demonstrated a high degree of criterion-related validity as various clinical groups had distinctly different profiles of scores (e.g., very large median effect size estimates for the difference between individuals with ADHD and individuals from the general population [Cohen’s d = 2.24 for Self-Report, see Figure 1; and Cohen’s d = 1.29 for Observer]), and scores from the CAARS 2 were able to correctly classify individuals from the General Population and those from clinical samples into their respective groups (overall correct classification statistics ranged from 84.7% to 92.5% across forms).
Updated and expanded norms
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.
CAARS 2: 10–20 minutes; CAARS 2–Short: 5-10 minutes; CAARS 2–ADHD Index: 1-3 minutes.