The CAARS 2 builds on the strong foundation established by the original CAARS. Advances to the original CAARS include not only improved, updated norms but also several refinements and enhancements to the measure’s structure and content. For more information on the development of this content, see chapter 6, Development, chapter 11, CAARS 2–Short, and chapter 12, CAARS 2–ADHD Index. These advances include the following (also see Tables 1.3 and 1.4):

• 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. Please see chapter 7, Standardization, for additional information about the Normative Sample, which was stratified based on age, gender, race/ethnicity, education level, and geographic region. An ADHD Reference Sample has been added to allow examiners to compare scores to those produced by others already diagnosed with ADHD. This reference group is useful when the scores are extreme in comparison with the Normative Sample and provides a helpful comparison for evaluating the severity of the reported problems (see chapter 7, Standardization, for more information; see also appendix K for information about the validity of the normative sample over time).
  
  
• Expanded upper age range. The oldest group in the original CAARS was 50 years and older; the CAARS 2 Normative Sample includes stratified samples for 50–59, 60–69, and 70+ years. This allows for a more valid assessment of older adults.
  
  
• Fair testing considerations. Fairness was a cornerstone of the development of the CAARS 2, with multi-cultural experts providing feedback on item content prior to data collection, and multiple analyses conducted to ensure that the CAARS 2 is not biased against any demographic group tested (see chapter 10, Fairness, for more information).
  
  
• Gender-inclusive language. The CAARS 2 uses gender-inclusive language for all test items. When interpreting CAARS 2 results, examiners may choose to retain the singular “they” or to ask individuals for their preferred pronouns.
  
  
• Spanish and French versions. In addition to English, the CAARS 2 Self-Report and Observer forms are also available in Spanish (North America) and French (Canada). Rather than simple translations of the words comprising the CAARS 2, these versions are linguistically and culturally sensitive adaptations of the English forms (see chapter 6, Development).
  
  
• Enhanced content. Dozens of new rationally-derived and empirically-evaluated items were added to the Content Scales, and the best-performing items from the original CAARS were retained.
  
  
  • Expanded and enhanced validity scales within a new Response Style Analysis section, including the new Negative Impression Index (designed to identify ratings that may be unrealistically negative or problem descriptions that may be exaggerated) and an improved Inconsistency Index (to capture inconsistent responding). The Response Style Analysis also includes Omitted Items (the total number of items that the rater omitted when completing the CAARS 2) and Pace (available for online administrations only; captures the average number of items completed per minute). For more information about the validity scales and Response Style Analysis, see chapter 4, Interpretation.
    
    
  • Included several reverse-scored items to avoid response tendencies produced when higher ratings always reflect greater difficulties.
    
    
  • Added Associated Clinical Concern Items to screen for issues that may require clinical follow-up (e.g., suicidality, self-harm, anxiety, depression).
    
    
  • Based on clinical utility and factor analyses, the CAARS 2 Content Scale items, scale structure, and scale names have been revised as follows:
    
    
    • The new Inattention/Executive Dysfunction scale expands upon the former Inattention/Memory Problems scale to better represent a range of executive function deficits that are often experienced by individuals with ADHD.
      
      
    • The original Hyperactivity/Restlessness scale has been relabeled Hyperactivity. The updated scale retains items covering subjective restlessness while also including items capturing verbal and motoric hyperactivity.
      
      
    • The previous Impulsivity/Emotional Lability scale has been split into distinct Impulsivity and Emotional Dysregulation scales to examine each area more widely.
      
      
    • The revised Negative Self-Concept scale includes new content to capture the self-esteem struggles experienced by many with ADHD, expanding the utility of the original Problems with Self-Concept scale.
      
      
  • DSM Symptom Scales have been updated and aligned with current DSM¹ symptom criteria.
    
    
  • Improved sensitivity and specificity of the CAARS 2‒ADHD Index. Statistical techniques that were unavailable when the original CAARS‒ADHD Index was developed were used to update the index and optimize its accuracy in discriminating between those with and without ADHD.
    
    
  • New items created to assess aspects of Impairment & Functional Outcome².
    
    
  • Included two open-ended Additional Questions to elicit rater comments about other issues/problems and strengths/skills.
    
    
• User-friendly, customizable reports. Each CAARS 2 report begins with an Overview that presents all CAARS 2 results, followed by tables of CAARS 2 scale scores, a glossary that provides helpful interpretive content, and a section that provides item-level responses by scale.
  
  
• Multiple reference samples. Examiners can now select multiple reference samples to include in the report. For example:
  
  
  • Compare different gender reference groups (e.g., Combined Gender, Male, and/or Female norms) in a convenient side-by-side graph. (See Understanding Reference Samples in chapter 3, Administration and Scoring for a discussion of reference sample considerations for various gender groups.)
    
    
  • Consider the results in reference to both a General Population Sample and an ADHD Reference Sample to examine how the individual being evaluated compares to a typical population and to individuals who have been diagnosed with ADHD.
    
    
• Easy transition from adolescent to adult Conners assessment tools. Increased alignment between the CAARS 2 and the Conners 4 (Conners, 2022) facilitates a lifespan approach to ADHD assessment/monitoring and simplifies the integration of information as adolescents transition into adulthood.
  
  
• Flexible, simplified purchase options. Each CAARS 2 purchase on the MHS Online Assessment Center+ can be used to generate reports for any of the CAARS 2 forms (Self-Report or Observer versions of the full-length CAARS 2, Short, or ADHD Index). This eliminates the need to monitor remaining balances for different forms. Reports can be accessed multiple times with no additional charges.