• Assessing an Individual
• Screening a Group
• Evaluating an Intervention
• Use in a Research Context

The CAARS 2 can be informative in many settings, including clinical assessment of individuals, group screenings, treatment/progress monitoring, evaluation of treatment protocols, and as a selection and/or outcome measure in research.

Assessing an Individual

The CAARS 2 can be used as a screening tool or as part of a comprehensive assessment of ADHD in adults. Although rating scale data alone are not sufficient for making an ADHD diagnosis, rating scales are regarded as an essential component of a multi-method, multi-informant ADHD evaluation. The CAARS 2 can inform clinical diagnosis and treatment planning by providing information on the nature, frequency, and/or severity of core and associated ADHD symptoms, the degree to which such symptoms deviate from age- and gender-based norms, and functional impairments related to those symptoms. The DSM Symptom Scales can assist clinicians in determining when the symptomatic criteria (DSM ADHD Criterion A) for the Predominantly inattentive, Predominantly hyperactive/impulsive, or Combined presentations of ADHD are present. The Total ADHD Symptoms scale provides a dimensional look at the overall symptoms of ADHD. Finally, the CAARS 2–ADHD Index is an empirically-derived scale composed of items that help differentiate individuals diagnosed with ADHD from those in the general population. Using both the CAARS 2 Self-Report and CAARS 2 Observer forms facilitates multi-informant assessments that enhance the quality of evaluations by offsetting possible informant biases, generating more comprehensive information, and providing evidence for the pervasiveness of symptoms across settings.

Screening a Group

In some instances, the examiner may wish to obtain information about members of a group instead of an individual, particularly in settings where resources are limited and waiting lists can be long. One group application involves using the CAARS 2 as a screening tool to identify individuals who might warrant a full ADHD evaluation or inclusion in a treatment program. For example, the CAARS 2 might be used to screen college students who are struggling academically to identify those who could benefit from a more complete, resource-intensive ADHD assessment. Incarcerated adults might also be screened with the CAARS 2 to select those most in need of additional support or therapeutic interventions.

Given that any single measure used for clinical screening purposes may carry the risk of over-identification or under-identification, it is critical to be particularly cautious about interpreting results obtained in these applications. It is only in the context of integrative corroborative evidence obtained from multiple methods (and, ideally, multiple informants) that firm clinical conclusions can be reached. The CAARS 2 results that are obtained in a screening context should therefore be qualified with a statement such as, “Scores on the following scales were elevated, which suggests the need for further evaluation.” Avoid over-interpreting results or drawing definitive clinical conclusions unless supporting data and the input of a qualified clinician are available.

Evaluating an Intervention

Results from the CAARS 2 can inform decisions about the effectiveness of a pharmacologic, psychosocial, or other treatment for ADHD, whether evaluating one person’s response to treatment or examining the efficacy of a treatment approach via group comparison studies (see the Comparing Results Across Different Points in Time section in chapter 4, Interpretation, for discussion about progress monitoring). For example, adult ADHD specialty clinics, university-based disability service offices, and correctional facilities might benefit from collecting repeated CAARS 2 forms from those receiving their services in order to evaluate the efficacy of the interventions provided. Likewise, a novel treatment approach might be assessed through the collection of group data. These group data can subsequently be analyzed to determine whether, on average, a statistically significant change (pre- versus post-treatment or treatment versus control group) occurred. CAARS 2 results can be collected at the beginning of an intervention to provide baseline data. Repeated administrations at several points throughout the intervention can help clinicians and program managers evaluate whether a particular intervention is associated with symptom and/or functional improvement. Results from these types of evaluations can be helpful in supporting the need for continuing, modifying, or even discontinuing treatment programs offered by a clinic. These data could also be used to justify the need for additional funding to expand the number of people served.

Use in a Research Context

The original CAARS has been used extensively in a broad range of research studies. Its sensitivity to changing symptoms made it a useful measure of treatment effects in studies employing a variety of research designs, including clinical trials of both psychosocial and pharmacologic treatments (e.g., Bilodeau et al., 2014; Phillipsen et al., 2015; Weisler et al., 2017; Wilens et al., 2006).

The current edition is also expected to play an important role in the scientific study of ADHD in adults, including research on the course of ADHD through the lifespan, the neurobiology of the disorder, and the efficacy of treatments. The CAARS 2 offers researchers several advantages. First, the scales were carefully developed to measure a wide spectrum of symptoms, behaviors, and outcomes associated with ADHD. Second, the scales’ strong psychometric properties can increase researchers’ confidence in the reliability and accuracy of their results. Third, the CAARS 2 provides a rich source of data and statistical information. Finally, the CAARS 2 is an efficient standardized test with short administration times, varying from 1 to 20 minutes, depending on the form used.

The CAARS 2 can be an invaluable tool for researchers, with respect to screening potential participants, contributing to diagnostic assessments for research group assignment, measuring response to extant psychosocial or pharmacologic treatments, or as an outcome measure in clinical trials investigating a new drug, digital therapeutic, or other intervention for ADHD. The scales’ strong psychometric properties, cultural fairness, validity scales, comprehensive coverage, DSM compatibility, inclusion of impairment and functional outcome items, multiple versions (e.g., different form lengths, different rater types), provision of the brief ADHD Index, and customizable online scoring capabilities all render it an ideal tool for adult ADHD research. For example, the T-scores provided by the online scoring will prove highly useful in the context of pharmaceutical trials where capturing extreme values may be important for characterizing both the participant pool and any therapeutic response.

Researchers are advised to take some special precautions regarding the interpretation of the CAARS 2 in a research setting. Despite the typical research focus on comparing average group responses, research protocols that involve qualified clinicians might also provide cautious interpretation of individual participant’s results. In such instances, the significant limits of such interpretations must be acknowledged (e.g., lack of a clinical interview, limited background information), as the full meaning of CAARS 2 results can only be provided when they are integrated with other pertinent information. Researchers might also discover scores that indicate potential clinical concerns in a research participant (e.g., endorsement of items pertaining to suicidal thoughts/attempts, self-injury, anxiety/worry, and sadness/emptiness). In such instances, ethical standards require that the research protocol establishes a means of taking responsible action to further evaluate, protect, and/or connect that individual with appropriate clinical services. Investigators need to be aware that the fundamental ethical requirements of informed consent and debriefing apply in research contexts as well as in clinical and screening situations. As part of informed consent procedures, the researcher must explain the nature of the research being conducted, any possible risks and benefits associated with participation, the right of the participant to withdraw from the study at any time without penalty, and the nature and purpose of the procedures and measures to be administered, including the CAARS 2. The debriefing should also cover the use of the CAARS 2 and other measures relevant to the particular research study.