Determining cutoff scores on the Conners' adult ADHD rating scales that can definitively rule out the presence of ADHD in a clinical sample

In recent years, the prevalence of Attention Deficit/Hyperactivity Disorder (ADHD) and the number of individuals seeking ADHD assessments has risen significantly, leading to an increased demand for accurate diagnostic tools. This study aimed to identify cutoff scores on the Conners' Adult ADHD Rating Scales (CAARS-S:L) that can definitively rule out the presence of ADHD. Among 102 clinically diagnosed adult ADHD participants and 448 non-ADHD participants who completed the CAARS-S:L, a receiver operating characteristic curve analysis established a perfectly discriminant cutoff T-score of <44 on the ADHD Symptoms Total subscale when looking at any ADHD diagnosis and <54 on the Inattentive Symptoms subscale when looking at individuals diagnosed with the inattentive subtype of ADHD. Alternative cutoffs of <54 (ADHD Symptoms Total subscale) and <63 (Inattentive Symptoms subscale) were also identified, both with a sensitivity of 0.95 or higher. Furthermore, the analysis found the ADHD Index to be a poor predictor of a negative ADHD diagnosis, suggesting against the use of this scale for cutoff determination. Despite this limitation, these findings indicate that with specific cutoffs, the CAARS-S:L may have the potential to conclusively rule out ADHD, effectively streamlining the diagnostic process and reducing unnecessary comprehensive assessments in clear negative cases.