Abstract:

Cognitive Disengagement Syndrome (CDS), also referred to as Sluggish Cognitive Tempo (SCT), involves a set of developmentally inappropriate and persistent behaviors (symptoms) that is characterized by attentional disengagement, conscious or effortful mental processing from the ongoing external context and hypoactivity. It is an emerging field that accompanies attention deficit hyperactivity disorder research.

Recently, Becker (2025) provided a broad overview of the history of the CDS construct, its terminology, and the current state of the science, and proposed ten key research domains and open questions. These include developmental course of CDS across the lifespan, mechanisms linking CDS to functional outcomes and impairment and so on. The study also discussed the possible conceptualizations of CDS as a distinct disorder, diagnostic specifier, or transdiagnostic dimension. However, Becker (2025) did not provide a detailed review of CDS cognitive function, only outlining research on CDS and processing speed. The review also did not address research into the brain mechanisms of CDS or systematically summarize the unique characteristics of CDS relative to other disorders. Therefore, this paper aims to further analyze the independent characteristics of CDS, based on Becker's (2025) theoretical framework, and clarify areas of consensus and disagreement.

This study reviews cognitive functioning impairment, social functioning impairment, and neural mechanisms of CDS and other related disorders. Studies on cognitive functioning impairment suggest that people with CDS exhibit impairments in mind wandering and behavioral regulation (e.g., self-control, emotional regulation, motivation). They also have difficulties with metacognition, such as time management, organization, problem solving, and working memory. However, further exploration is needed in areas such as attention networks, selective attention, and processing speed. Research on social functioning impairment indicates that the CDS population exhibits impairments in academic performance, sleep, peer rejection, and internalizing symptoms, such as anxiety, depression, withdrawal/shyness, autistic traits, and somatic discomfort. They also have difficulties with externalizing symptoms, such as oppositional defiant disorder, impulsivity, and aggression. Further research is required into areas such as procrastination, internet gaming disorder, and social anxiety. In terms of neural mechanisms, most evidence suggests that CDS is associated with abnormalities in the dorsal attention network and the default mode network. CDS also differs from ADHD groups in terms of white matter structure, theta/beta ratio (TBR) in the frontal and central frontal regions, and task-activated brain regions. However, these findings require further validation. In summary, a growing body of evidence supports the conceptualization of cognitive disengagement syndrome as a standalone mental disorder characterized by cognitive and social functioning impairment, and distinct brain mechanisms compared to ADHD and related disorders.

However, CDS research remains in its early stages of development, and future research can explore the following areas: (1) Clarify CDS as an independent disorder, further elucidate the specific impairments and heterogeneity in cognitive and brain function associated with CDS compared to other related psychological disorders. It is also necessary to further distinguish the differences and connections between CDS and broader related psychological symptoms; (2) Focus on the developmental course of CDS characteristics across the lifespan, supplementing samples from early childhood, adolescence, and adults who are not university students. Conduct longitudinal studies to measure and track CDS throughout childhood development, enabling a more comprehensive observation of the course of functional impairments and brain mechanisms in CDS populations over time, and revealing the dynamic patterns of CDS characteristics; (3) Clarify whether CDS is a unidimensional or multidimensional structure. In addition to exploring the relationship between the overall CDS construct and its subdimensions, research should focus on how to integrate the abundant existing research on these subdimensions into a comprehensive CDS theoretical framework; (4) Enrich CDS research methods. Future research should incorporate more sensitive or ecologically valid subjective and objective methods and explore the potential adaptive significance of CDS characteristics from a positive psychology perspective. Additionally, behavior and brain mechanism studies can be conducted based on the latest definition of CDS to further explore the interactions between CDS functional impairment characteristics and their causal process models, thereby revealing the underlying mechanisms of CDS-specific functional impairments.

Key words: cognitive disengagement syndrome, cognitive functioning impairment, social functioning impairment, neural mechanisms