• Length
• Language
• Rater
• Format
• Age Ranges
• Reading Levels

Length

The CAARS 2 is available as a full-length form (CAARS 2), a Short form (CAARS™ 2–Short), and an ADHD Index form (CAARS™ 2–ADHD Index), each of which has Self-Report and Observer versions (see Rater, later in this section for more information). Table 1.1 provides a comparative overview of the content of these CAARS 2 forms.

Ideally, multiple raters (the individual being evaluated and one or more people who know that person well) should complete the same length of the CAARS 2 form in order to facilitate the comparison and integration of results. However, meaningful results can still be obtained even when different forms are used across raters.

Deciding which form to administer will depend largely on the purpose of the assessment and how much time the rater has available (see Administration Time in chapter 3, Administration and Scoring, for details on completion times for each form).

The 97-item full-length CAARS 2 form includes all CAARS 2 items and scales. The full-length form is typically used when comprehensive information is sought, such as an initial evaluation or periodic re-assessment to detect any changes in core and associated features of ADHD.

The CAARS 2–Short form (55 items for the Self-Report, 52 items for the Observer) contains key items from each of the CAARS 2 Content Scales. It also includes the Negative Impression Index, Omitted Items, Pace, the ADHD Index, and two open-ended Additional Questions (about other problems and strengths). Although it takes less time to complete than the full-length form, the short form is not as comprehensive as it has both fewer scales and fewer items per scale. (Note that the CAARS 2–Short does not include the DSM Symptom Scales, the Associated Clinical Concern Items, the Impairment & Functional Outcome Items, or the Inconsistency Index; see appendix A for itemized content of full-length and short forms.) The short form is useful when a rater has limited time, or when the rater will be asked to complete the CAARS 2 multiple times (e.g., monthly assessment of treatment response, medication trials).

The CAARS 2–ADHD Index form contains the 12 items from the full-length form that best differentiate individuals diagnosed with ADHD from those in the general population. This form is useful when circumstances call for a very brief assessment (e.g., repeated assessments for treatment monitoring or gathering research data) that can effectively discriminate responses likely to be produced by individuals with ADHD as opposed to those from the general population. It can also provide a very quick initial screen to determine if further ADHD evaluation is warranted, particularly for pre-evaluation or group screening purposes.

Language

Translations of the English language version of the CAARS 2 have been developed for the Spanish-speaking population in North America and the French-speaking population in Canada. These versions are linguistically and culturally sensitive adaptations of the English forms (see chapter 13, Translations, for information on the development of these versions). To ensure that the rater can understand the items and respond accordingly, the examiner should select the most suitable language based on the rater’s language proficiency. This selection can be done on the MHS Online Assessment Center+.

Rater

The CAARS 2 Self-Report form provides information about a person’s perceptions of their own thoughts, feelings, behaviors, and functioning. The CAARS 2 Self-Report can be completed by adults who are 18 years and older.

Ideally, at least one CAARS 2 Observer form will be completed whenever a self-report form is administered. Observers should be familiar with the day-to-day functioning of the person being evaluated. As such, common collateral informants on observer forms include spouses/romantic partners, parents/guardians, adult children, other relatives, friends, and co-workers.

Collecting ratings from multiple observers and from the person being evaluated (self-report) provides a broad understanding of the individual’s behaviors and symptoms across various settings, which is important when considering a possible diagnosis of ADHD and planning interventions.

Format

Administering the CAARS 2 online (see Administration Settings in chapter 3, Administration and Scoring) is recommended given its speed and convenience. Examiners can either set up a local administration or email a link to the test directly to the rater. Online administration precludes skipped or omitted items by prompting raters that no response has been provided and requiring the rater to indicate that they intend to skip the item before they can advance. Examiners can also choose to print a paper form from the MHS Online Assessment Center+ for instances where a rater does not have reliable internet service or otherwise requires a hard copy.

Age Ranges

The CAARS 2 was developed to evaluate symptoms of ADHD and associated features in adults aged 18 years and older. In most cases, the Conners 4th Edition (Conners 4™; Conners, 2022) is more appropriate when assessing an individual under 18 years. However, if a need or preference arises to evaluate an adolescent approaching the age of 18 with the CAARS 2, the automated scores produced will be based on the youngest available normative group (viz., 18–24 years) and accompanied by a statement that the results must be interpreted with caution given the absence of age-matched normative data.

Reading Levels

The CAARS 2 was developed at the lowest reading level possible while still ensuring appropriate content coverage. The reading level of the CAARS 2 is significantly lower (typically by about 2 grade levels) than that of the original CAARS¹. Table 1.2 identifies reading levels for each English-language version of the CAARS 2 forms. The reading level corresponds to the grade level required for reading and comprehending item content and test instructions (e.g., a reading level of 4.5 indicates that the items can be read by an average student halfway through the fourth grade). Reading levels for the CAARS 2 were determined with the Flesch-Kincaid Grade Level Formula (Flesch, 1948; Kincaid et al., 1975). This formula produces a readability score that is a function of the total number of words, syllables, and sentences in the analyzed text.

In general, the CAARS 2 Self-Report should be accessible to most adults who have completed elementary school. The CAARS 2 Observer has a slightly higher reading level. Alternative administration methods may be needed for raters with reading skills below the fifth-grade level (for Self-report) or the seventh-grade level (for Observer; see Verbal Administration section of the Modified Administration of the CAARS 2 in chapter 3, Administration and Scoring).