Sluggish cognitive tempoTowards establishing the diagnostic validity

Laburpena

Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common psychiatric disorders in childhood worldwide. However, there are some children who display attention problems that are not captured by ADHD diagnosis but are better characterized by excessive daydreaming, mental confusion, drowsiness/sleepiness, and slowed behavior/thinking. These symptoms have been termed Sluggish Cognitive Tempo (SCT) and it has recently been argued that SCT, yet strongly related to, may be differentiated from the inattention symptoms of ADHD (ADHD-IN), and also associated with other mental health, academic, and socioemotional impairments. The aim of this thesis is to contribute to the advance toward a better definition and understanding of the SCT dimension. To satisfy this aim, this thesis involved three specific objectives: (1) the identification of an optimal set of symptoms for assessing SCT across multiple informants (i.e., mothers, fathers, teachers, and child self-reports); (2) to determine the common and unique external correlates of SCT relative to ADHD-IN; and (3) to determine if SCT and ADHD can be clinically differentiated from each other. This thesis used a large, school-based sample of 2,142 unique children (ages 8–13, 50.51% boys) with multi-informant design. Mothers, fathers, and teachers completed measures that assess SCT, ADHD, and other different psychopathology symptoms and functional impairment. Children completed measures of SCT, loneliness, and preference for solitude. The most relevant findings to emerge from this thesis show: First, the identification of 15 SCT symptoms as an appropriate standard symptom set for assessing SCT in children across multi-informants. Second, empirical support for the reliability and validity of a child self-report measure of SCT as part of a multi informant assessment of SCT. Third, SCT and ADHD-IN showed different and unique associations with other symptoms and impairment factors. Fourth, clinically elevated SCT or ADHD differed in their patterns of co-occurring externalizing and internalizing symptoms, social functioning, and academic impairment. Fifth, this thesis also reported the distinction, as well as co-occurrence, of elevated SCT symptoms with depression in addition to ADHD. In sum, this thesis moves the field toward examining both the empirical and clinical differentiation of SCT and ADHD. In particular, the use of a common set of symptoms might help to advance the understanding of the SCT construct, as well as, the unique contribution of different informants and their utility with specific contexts to guide evidence-based recommendations for assessing SCT. Besides, these findings might contribute as a base for understanding how SCT could be part of diagnostic nosologies and models of psychopathology.