Abstract
Despite increasing interest in sluggish cognitive tempo (SCT) in children, the field is stymied by the lack of a standard symptom set that can be used across studies. Without a standard symptom set, it is difficult to determine if differences across studies are due to methodological or sample differences, or simply the way SCT was measured. To move the field toward a standard symptom set, this study evaluates a teacher-report rating scale of SCT revised based on recent meta-analytic findings that identified optimal items for distinguishing SCT from attention-deficit/hyperactivity disorder inattention (ADHD-IN). Participants were 1,349 students (50.7% male) from grades 2 to 5. Teachers provided ratings of SCT, ADHD-IN, academic impairment, and social impairment. Exploratory structural equation modeling found 15 of the 16 SCT items to demonstrate excellent convergent validity and discriminant validity with ADHD-IN. The measurement properties of the SCT construct were also invariant across sex. SCT was uniquely associated with both academic and social impairment above and beyond ADHD-IN and sex. Although replication and extension is needed, the current study provides the strongest evidence to date of a possible standard symptom set that can be used across studies examining SCT in children.