Sluggish cognitive tempo in children referred to a pediatric Sleep Disorders Center: Examining possible overlap with sleep problems and associations with impairment

Clinical characterization of children and adolescents with ADHD and sleep disturbances

Sleep disturbances (SD) are commonly reported concerns among parents and caregivers of children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD). While it is widely acknowledged that SD can worsen various aspects of children and adolescents' well-being (e.g., academic performance and emotional/behavioral state), a comprehensive clinical characterization of ADHD and SD is currently lacking. To address this gap, 136 children and adolescents diagnosed with ADHD (aged 6 to 14 years) were retrospectively selected by reviewing electronic health records of hundreds of patients with neuropsychiatric disorders referred to the children's hospital. Participants were divided into two groups based on the presence of SD, assessed via a parent-report questionnaire (94 ADHD without SD and 42 ADHD with SD). Standardized measures of adaptive behavior, academic performance, ADHD-related and emotional/behavioral symptoms were collected. Results documented that the group of ADHD with SD obtained worse scores in specific aspects of adaptive behavior (conceptual and practical domains), academic performance (text comprehension, writing), ADHD symptoms (inattention) and emotional/behavioral difficulties (especially, mood/emotional regulation and stress) compared to those with ADHD without SD. In addition, our results established a relationship between sleep problems and diverse clinical aspects of children and adolescents with ADHD, while controlling for age, cognitive level, gender, ADHD symptoms severity, and Body Mass Index. From a clinical perspective, our study suggests that the presence of SD in patients with ADHD may serve as an indicator for strengths and weaknesses in this population, even demonstrating an independent relationship with specific clinical dimensions. Implications to improve clinical diagnostic and therapeutic interventions are discussed.

Examining ADHD and Cognitive Disengagement Syndrome Symptoms in Relation to Food Insecurity in Early Adolescents

Approximately 13.8 million U.S. households face food insecurity, which severely affects child development, with more than half of these households including children. Research links food insecurity to cognitive deficits and mental health challenges, highlighting the need for thorough understanding and intervention. Although existing studies have explored the association between food insecurity and internalizing symptomatology, less research has examined food insecurity in relation to attention-deficit/hyperactivity disorder (ADHD) symptoms. Further, no studies have explored the connection between food insecurity and cognitive disengagement syndrome (CDS) symptoms, closely related to ADHD symptoms. Despite extant research linking CDS to environmental factors, empirical attention to its potential association with food insecurity is notably lacking. Additionally, adolescents, almost twice as likely as younger children to experience household food insecurity, are likely more aware and respond differently to challenges during this developmental period. Accordingly, this study investigated the unique associations of parent-, teacher-, and youth self-reported ADHD dimensions and CDS symptoms in relation to parent-reported food insecurity in early adolescents (N = 136, ages 10-12). Controlling for age, sex, race, and medication use, no informant's ratings of ADHD symptom dimensions were uniquely related to food insecurity. In contrast, higher parent-, teacher-, and youth self-reported CDS symptoms were uniquely associated with greater food insecurity. This finding was robust to additional control of family income for teacher- and youth self-reported CDS symptoms. These findings highlight the complex link between food insecurity and mental health, suggest a connection with CDS symptoms, and stress the need to address food insecurity as a public health priority, especially in early adolescence.

Cognitive disengagement syndrome (sluggish cognitive tempo) and medical conditions: a systematic review and call for future research

Cognitive disengagement syndrome (CDS, previously referred to as sluggish cognitive tempo) is a unique set of symptoms distinct from ADHD inattentive symptoms that appear to be independently associated with neuropsychological and psychosocial outcomes in community and ADHD-specific samples of youth. However, our understanding of CDS in individuals with chronic or complex medical conditions is limited. The current systematic review is the first to summarize the literature on CDS prevalence rates and associations with neurocognitive and functional outcomes in youth with medical conditions, and to discuss areas of future research to guide clinical intervention. We conducted literature searches across four major databases and included studies assessing prevalence estimates, associations with neuropsychological and/or psychosocial functioning, or predictors of CDS in individuals with chronic or complex medical conditions. Twenty-five studies were identified and retained. Fifteen of sixteen studies reported elevations in CDS symptoms, though findings were mixed in studies comparing mean differences to typically developing youth. Seven studies provided inconsistent evidence for CDS being associated with neuropsychological or academic functioning, with six studies demonstrating consistent effects on psychosocial functioning. Finally, nine studies identified biological and sociodemographic factors associated with CDS, though almost all await replication. CDS symptoms are significantly elevated in youth with medical conditions and appear to be particularly linked with psychosocial functioning. Future research is needed to identify prevalence of CDS across a range of medical conditions, examine associations with neuropsychological and psychosocial functioning, and examine whether CDS impacts self-management.

[Formula: see text] Cognitive disengagement syndrome in pediatric patients with long COVID: associations with mood, anxiety, and functional impairment

Children with long COVID often report symptoms that overlap with cognitive disengagement syndrome (CDS, previously sluggish cognitive tempo (SCT)), a set of behaviors distinct from attention-deficit/hyperactivity disorder (ADHD) including excessive daydreaming, mental fogginess, and slowed behavior and thinking. Those with long COVID also frequently report low mood and anxiety, which are linked to CDS. The relationships between cognitive difficulties, mood, and functional impairment have yet to be explored in pediatric long COVID. Specifically, it is unclear how much cognitive difficulties (CDS, inattention) contribute to functional impairment, when accounting for mood/anxiety symptoms in this population. Retrospective parent-reported data was collected from 34 patients with long COVID (22 females, Mage = 14.06 years, SD = 2.85, range 7-19) referred for neuropsychological consultation through a multidisciplinary Post-COVID-19 clinic. Compared to community and clinically referred samples, on average, long COVID patients showed elevated CDS symptoms, including Sluggish/sleepy (e.g., fatigue) and Low Initiation subscales (e.g., difficulty performing goal directed behaviors). Low Initiation, mood, anxiety, and inattention were associated with functional impairment. In multiple hierarchical regression models, after controlling for mood and anxiety, Low Initiation and inattention were no longer predictive of functional impairment. Instead, anxiety remained the sole predictor of functional impairment. Our results demonstrate that children with long COVID have high levels of CDS symptoms. The association between cognitive difficulties and functional impairment dissipated with the inclusion of mood and anxiety, suggesting behavioral health interventions targeting anxiety may help improve daily functioning and quality of life in pediatric long COVID patients.

Assessing the mediating relationships between psychological factors in children with attention deficit hyperactivity disorder and cognitive disengagement syndrome

This study aims to investigate the predictive and mediating relationships between emotion dysregulation, internalizing disorders, family functionality, loneliness preference, and executive functions (EF) in children with attention deficit hyperactivity disorder and cognitive disengagement syndrome (ADHD + CDS). This study included 176 children and adolescents (92 boys, 84 girls) who were diagnosed with ADHD + CDS according to the Diagnostic and Statistical Manual of Mental Disorders, the Fifth Edition criteria by a fellowship-trained child and adolescent psychiatrist, between ages 8 -12 (M = 10, SD = 1.52) with a convenience sampling method. The solitude scale for children, difficulties in emotion dysregulation scale, Child Behavior Checklist, Barkley Sluggish Cognitive Tempo Scale, Family assessment device, and CNS Vital Signs test were used. The results showed that difficulty in emotion regulation, preference for loneliness, internalizing disorders and CDS symptom severity did not have a mediating effect between family functionality and EF. Still, emotion dysregulation mediates the relationship between EF and internalizing disorders by itself and through loneliness preference. Also, preference for loneliness and emotion dysregulation had a mediating effect between family functionality and internalizing disorders. Finally, it was found that the effect of emotion regulation difficulty, loneliness preference, and internalizing disorders had a mediating role between CDS symptom severity and family functionality. In conclusion, the information obtained from this study on the etiology of CDS may guide future studies.

The Challenges of Distinguishing Cognitive Disengagement Syndrome from Childhood Absence Epilepsy in Clinical Settings

We evaluated clinical parameters distinguishing cognitive disengagement syndrome (CDS) and childhood absence epilepsy (CAE). 40 children with CDS, 27 with CAE, and 41 controls aged 7-12 were compared regarding sleep problems, CDS, and ADHD symptoms. CDS-sluggishness symptoms, but not CDS-daydreaming symptoms, were significantly higher in CDS group than CAE group. CDS scale provided a weak discrimination value between CDS and CAE. Sleep problems and ADHD symptoms were similar between the two clinical entities. These findings highlight that CDS and CAE might have overlapping symptoms. 'Daydreaming' symptoms but not 'sluggishness' symptoms seem to be main overlapping manifestations between CDS and CAE.

Cognitive Disengagement Syndrome and Child Sleep Problems in ADHD, Anxiety and Depression

The main objective of this study was to analyse the relationship and differential contribution of Cognitive Disengagement Syndrome (CDS) and sleep problems in children in different psychopathological measures. A total of 1133 participants (612 fathers/mothers and 521 children aged 7-13 years in Years 3-6 of Primary Education) completed the scales on CDS, sleep problems, depression (DEP), anxiety (ANX) and attention deficit and hyperactivity disorder (ADHD). Similar and significant correlations were identified in the measures of CDS and sleep problems between fathers and mothers, obtaining a high coefficient between the two parents. However, weak correlations were found between fathers/mothers and children. The scores of CDS and the sleep disturbance scale for children (SDSC) significantly predicted the internalising measures and ADHD, especially between SDSC and DEP. It was confirmed that sleep problems had a greater presence in the group of children with the highest ADHD scores, and especially in CDS and ADHD jointly. To conclude, the data indicate the importance of sleep problems in understanding CDS and its relationship with other psychopathological measures, especially ADHD, although to a greater extent with internalising symptoms, especially DEP.

Report of a Work Group on Sluggish Cognitive Tempo: Key Research Directions and a Consensus Change in Terminology to Cognitive Disengagement Syndrome

OBJECTIVE

The aim of this work was 2-fold: (1) to evaluate current knowledge and identify key directions in the study of sluggish cognitive tempo (SCT); and (2) to arrive at a consensus change in terminology for the construct that reflects the current science and may be more acceptable to researchers, clinicians, caregivers, and patients.

METHOD

An international Work Group was convened that, in early 2021, compiled an online archive of all research studies on SCT and summarized the current state of knowledge, noted methodological issues, and highlighted future directions, and met virtually on 10 occasions in 2021 to discuss these topics and terminology.

RESULTS

Major progress has been made over the last decade in advancing our understanding of SCT across the following domains of inquiry: construct measurement and stability; genetic, environmental, pathophysiologic, and neuropsychological correlates; comorbid conditions; functional impairments; and psychosocial and medication interventions. Findings across these domains are summarized, and potential avenues to pursue in the next generation of SCT-related research are proposed. Following repeated discussions on terminology, the Work Group selected "cognitive disengagement syndrome" (CDS) to replace "SCT" as the name for this construct. This term was deemed to best satisfy considerations that should apply when selecting terms for a condition or syndrome, as it does not overlap with established terms for other constructs, is not offensive, and reflects the current state of the science.

CONCLUSION

It is evident that CDS (SCT) has reached the threshold of recognition as a distinct syndrome. Much work remains to further clarify its nature (eg, transdiagnostic factor, separate disorder, diagnostic specifier), etiologies, demographic factors, relations to other psychopathologies, and linkages to specific domains of functional impairment. Investigators are needed with interests and expertise spanning basic, clinical, and translational research to advance our understanding and to improve the lives of individuals with this unique syndrome.

Sluggish cognitive tempo, eating habits, and daytime sleepiness in obese adolescents

OBJECTIVE

Rates of obesity have risen steeply in the western world in all age groups. Sluggish Cognitive Tempo (SCT) is characterized by a cluster of symptoms. Daytime sleepiness, commonly seen in obesity, may share a similar origin with sleepiness and daydreaming symptoms of SCT. This study aims to investigate the relationship between obesity, SCT, daytime sleepiness, and eating habits.

METHOD

Adolescents, aged between 10-17 years, with a BMI >95^th centile, were recruited to the study. Clinical interviews were supplemented with standardized questionnaires.

RESULTS

Of the 35 adolescents, more than one quarter (N = 10, 28.6%) had SCT. Emotional overeating and food enjoyment subscale scores showed moderate correlations with the SCT scores, though these associations were not significant when controlling for ADHD symptoms. Daytime sleepiness score in adolescents with SCT was found to be significantly higher than those without.

CONCLUSION

Sluggish Cognitive Tempo is frequently present in adolescents with obesity and associated with higher levels of emotional overeating, food enjoyment, and daytime sleepiness. Targeting aspects of SCT might offer additional avenues to assist in weight management programs for youth.

Sluggish cognitive tempo: Association with neuropsychological test scores, motor incoordination, and dysgraphia in elementary school children

Research on the relationship between sluggish cognitive tempo (SCT) and scores on neuropsychological tests (such as those measuring processing speed and reaction time) is inconclusive, and the association between SCT and motor incoordination and dysgraphia has not been objectively investigated. Mothers of 413 elementary school children (6-12 years of age) rated their children on the Pediatric Behavior Scale (PBS), which yields psychological problem scores, including SCT. Children were administered an extensive battery of neuropsychological tests assessing processing and performance speed, working memory, immediate and delayed recall, sustained attention, response inhibition, cognitive flexibility, fine motor manipulative skill, verbal fluency and retrieval, set shifting, and interference control, as well as intelligence and reading and math achievement. Only three of the 19 correlations between SCT and neuropsychological scores were significant, and all involved graphomotor tests (two timed and one untimed). In regression analysis, the strongest independent predictor of SCT was the maternal PBS incoordination factor score, followed by ratings of autism, inattention, and depression. Neuropsychological test scores did not contribute significantly more to predicting SCT. Among the incoordination PBS factor items, clumsy and draws or writes poorly were significant SCT predictors. Our novel and unexpected findings showed that motor incoordination was a stronger correlate of SCT than other variables assessed in our study, including those previously linked with SCT. Future SCT research needs to include measures of incoordination and dysgraphia in order to replicate and expand upon the current findings. Our results suggest that SCT traits are not reliably measured by currently available neuropsychological tests.

Sluggish Cognitive Tempo (Cognitive Disengagement Syndrome) and Academic Functioning: A Systematic Review and Agenda for Future Research

The past two decades have witnessed substantial interest in sluggish cognitive tempo (SCT), a set of symptoms (e.g., excessive daydreaming, mental confusion, slowed behavior) distinct from attention-deficit/hyperactivity disorder (ADHD) and other psychopathology symptoms. Despite evidence linking SCT to a range of functional outcomes, findings for academic functioning are unclear. The current review summarizes the literature on SCT and academic functioning and offers an agenda for future research. A systematic review was conducted to identify studies assessing SCT and academic outcomes, including academic impairments and performance, in childhood, adolescence, and young adulthood. Sixty studies were retained (53 cross-sectional, 7 longitudinal) from 44 separate samples, with the majority (n = 32, 53%) assessing global ratings of academic impairment and fewer measuring specific academic domains or standardized achievement test scores. Findings were generally consistent in showing SCT to be correlated with global ratings of academic impairment, lower grades, and inconsistently associated with poorer math and reading scores. Findings were more mixed when controlling for ADHD symptoms, intelligence, and/or demographic factors. Overall, SCT is associated with poorer academic functioning, although inconsistencies and key limitations are common across studies. Ten directions for future research are offered to advance understanding of how SCT may be associated with or impact academic functioning.

A multi-method examination of sluggish cognitive tempo in relation to adolescent sleep, daytime sleepiness, and circadian preference

BACKGROUND

The field's understanding of the association between sluggish cognitive tempo (SCT) and sleep is severely limited by the lack of multi-method and multi-informant research designs that move beyond global ratings, often focused on a limited number of sleep-related domains, such as daytime sleepiness. The current study begins to address these limitations by using actigraphy, daily sleep diary, and self- and parent-report global ratings of sleep in adolescents, a developmental period marked by changes in SCT, sleep, and circadian function. As SCT and sleep are also associated with ADHD symptoms, we tested these associations in a sample of adolescents with and without ADHD.

METHODS

Adolescents (N = 302; M age = 13.17 years, 44.7% female) with (n = 162) and without ADHD (n = 140) and parents completed global ratings of sleep and daytime sleepiness, and adolescents completed a measure of circadian preference. Adolescents also wore actigraphs for approximately two weeks, during which daily diaries were completed.

RESULTS

Above and beyond demographic characteristics (i.e., sex, race, and family income), pubertal development, medication use, and ADHD group status, adolescents' self-reported SCT symptoms were uniquely associated with shorter sleep duration and later sleep onset per both actigraphy and daily diary. SCT symptoms were also uniquely associated with longer sleep onset latency and poorer overall sleep (per daily diary), more sleep/wake problems and daytime sleepiness (per adolescent rating), more difficulties initiating and maintaining sleep (per parent rating), and later eveningness preference (per adolescent rating). Nearly all significant effects remained in sensitivity analyses controlling for adolescent- or parent-reported ADHD symptom dimensions.

CONCLUSIONS

Findings provide the strongest evidence to date for SCT being uniquely linked to poorer sleep, greater daytime sleepiness, and a later evening circadian preference across subjective and objective measures. Longitudinal studies are needed to evaluate predictive and bidirectional associations.

The Associations Between Sluggish Cognitive Tempo, Internalizing Symptoms, and Academic Performance in Children With Reading Disorder: A Longitudinal Cohort Study

OBJECTIVE

To investigate whether sluggish cognitive tempo (SCT) was associated with anxiety, depression, and academic performance (AP) in children with reading disorder (RD), and whether ADHD-Inattention (ADHD-IN) moderated these relationships.

METHOD

Parents and teachers of children with RD (N = 147, ages 6-18) completed evaluations of SCT, ADHD, anxiety, depression, and AP, every 3 months for 18 months. Baseline and longitudinal associations between SCT and outcomes, and effect moderation of ADHD-IN, were assessed.

RESULTS

Teacher-rated SCT was positively associated with teacher-rated anxiety (p < .001) and negatively associated with AP (p < .001) cross-sectionally and longitudinally, with significant effect modification by ADHD-IN for both outcomes. SCT was not associated with depression in adjusted cross-sectional and longitudinal analyses. There were no significant findings for any parent-reported measures.

CONCLUSION

SCT has negative effects on anxiety and AP in children with RD among individuals with low ADHD-IN according to teacher report. Targeted treatment of SCT may provide substantial benefits.

Abnormal physiological responses toward sensory stimulus are related to the attention deficits in children with sluggish cognitive tempo

Previous studies have found that sluggish cognitive tempo (SCT) is often associated with difficulties in real-life functioning, such as social problems, emotional difficulties, and academic learning difficulties. However, the underlying mechanisms contributing to the SCT symptoms and its associated real-life difficulties have still not been clearly understood. A previous study has found that SCT symptoms were associated with hypoarousal and hyperarousal toward the sensory stimulus. However, it is still unclear whether such abnormal arousal regulation is related to sustained attention difficulties that have been found to be related to social difficulties and withdrawn behavior in children with SCT. In this study, arousal regulation deficit in SCT is examined by the physiological responses quantified by HRV and EEG in the sensory challenge paradigm. This study aimed to establish a linkage between arousal regulation reflected by HRV and EEG and attention difficulties in children with SCT. The results of this study showed that higher theta power in the auditory stimulation condition than in the resting condition was associated with higher omission errors in sustained attention tasks in the SCT group. It was also found that higher parasympathetic activities during sensory stimulation conditions were associated with higher commission errors in the SCT group. These results reflected that hypersensitivity toward stressful sensitivity toward a stressful sensory stimulus is associated with attention difficulties in children with SCT. This further supported the notion that SCT should be conceptualized as a condition characterized by multiple deficits in different biological systems, such as the cognitive system, the negative valence system, and the arousal regulatory system.

"My mom calls it Annaland": A Qualitative Study of Phenomenology, Daily Life Impacts, and Treatment Considerations of Sluggish Cognitive Tempo

Objective: To conduct qualitative analysis of interviews to understand phenomenology, daily life impact, and treatment considerations of sluggish cognitive tempo (SCT) behaviors in children and adolescents. Method: Youth with elevated SCT symptoms (N = 15, ages 9-16 years) and their parents completed interviews focused on their perception and daily life impact of SCT behaviors. Parents were also asked about intervention targets. Results: Parents and youth had both negative and positive perceptions of SCT, with SCT fostering creativity/imagination and a break from stressors while also negatively impacting daily functioning. The domains most frequently selected by parents as SCT intervention targets were academics, emotions, mind wandering, morning routines, and self-esteem. Conclusion: Children and their parents share negative and positive views of SCT behaviors, while also detailing specific ways that SCT negatively impacts day-to-day functioning. This study offers insights into possible intervention targets as provided by youth and parents directly impacted by SCT.

Sluggish Cognitive Tempo and Daytime Sleepiness Mediate Relationships Between Sleep and Academic Performance

OBJECTIVE

Sleep difficulties, daytime sleepiness, and sluggish cognitive tempo (SCT) are associated with impairments in academic performance. SCT refers to symptoms of sluggishness, tiredness/lethargy, and slowed thinking/processing, but despite symptom overlap with sleepiness, research examining interrelations of SCT with sleep and daytime sleepiness is limited. The aims of this study were to evaluate the relationship between SCT and daytime sleepiness and to examine pathways between sleep, daytime sleepiness, SCT, and academic performance.

METHOD

Participants were a community sample of 1628 parents/caregivers of children aged between 6 and 10 years who completed questionnaires about their child's behavior, sleep, and academic performance. Confirmatory factor analysis was used to examine whether SCT was distinct from daytime sleepiness. Then, structural equation modeling was used to examine direct and indirect pathways between sleep (sleep-disordered breathing [SDB] symptoms, sleep duration, and latency), daytime sleepiness, SCT, and academic performance in reading, writing, and math.

RESULTS

SCT and daytime sleepiness were distinct but moderately correlated (r = 0.33, p ≤ 0.001). Sleep, in particular SDB symptoms, predicted increased SCT and daytime sleepiness. SCT was directly and negatively associated with all domains of academic performance, daytime sleepiness was associated with poorer reading performance, and longer sleep duration was directly associated with poorer math performance. SCT and, to a lesser extent, daytime sleepiness mediated effects of sleep on academic performance.

CONCLUSION

SCT symptoms are important for understanding how sleep difficulties affect academic performance in children. Sleep, daytime sleepiness, and SCT are interrelated but distinct factors that affect children's academic performance.

Systematic Review: Assessment of Sluggish Cognitive Tempo Over the Past Decade

OBJECTIVE

To conduct a systematic review of the measures designed to assess sluggish cognitive tempo (SCT) since the first SCT scale using careful test-construction procedures was published in 2009.

METHOD

MEDLINE (PubMed), Embase, PsychINFO, and Web of Science databases were searched from September 2009 through December 2019. Articles reporting on reliability (internal consistency, test-retest, and interrater reliability), structural validity (an aspect of construct validity focused on items' convergent and discriminant validity), concurrent and longitudinal external validity, invariance, or intervention/experimental findings were included.

RESULTS

Full criteria for data extraction and inclusion were met by 76 studies. Nine measures for assessing SCT were identified (7 assessing parent report, teacher report, and/or self-report in children and 2 assessing self-report and/or collateral informant report in adults). Each measure demonstrated acceptable to excellent reliability. All or at least the majority of SCT items on each measure also had structural validity (high loadings on an SCT factor and low loadings on an attention-deficit/hyperactivity disorder [ADHD] inattention factor). Studies have supported the invariance of SCT across sex and time, and there is initial evidence of invariance across informants, youths with ADHD and youths without ADHD, and ADHD presentations. The Child and Adolescent Behavior Inventory (CABI), Child Concentration Inventory, Second Edition (CCI-2), and Barkley Adult ADHD Rating Scale-IV (BAARS-IV) have particularly strong support for assessing parent/teacher-reported, youth self-reported, and adult self-reported SCT, respectively.

CONCLUSION

The SCT measures included in this review share numerous positive properties, have promising psychometric support, and have proven useful for examining the external correlates of SCT across the life span. Although substantial progress has been made over the last decade, work remains to be done to further improve the assessment of SCT and key directions for future research are provided.

Relationship between sluggish cognitive tempo and sleep, psychological, somatic, and cognitive problems and impairment in children with autism and children with ADHD

Sluggish cognitive tempo (SCT) is a topic of renewed interest. Much remains to be learned about its association with symptoms and diagnoses that have received little research attention, particularly sleep disturbance, somatic complaints, and autism. Our study is the first to explore the relationship between SCT and sleep, internalizing, externalizing, somatic, and cognitive problems, impairment, and demographics in large samples of children with autism, ADHD-Combined, and ADHD-Inattentive. Mothers rated 1,436 children with autism and 1,056 with ADHD without autism, 2 to 17 years, on the Pediatric Behavior Scale (PBS). Factor analysis yielded a 6-item SCT factor (sluggish/slow moving/low energy, stares/preoccupied/in own world, tires easily, in a fog/confused, drowsy/sleepy/not alert, and apathetic) plus 10 additional factors. SCT was distinct from but related to several factors and was associated with social and academic impairment. The strongest independent predictors of SCT were depression, sleeping more than normal, cognitive problems, autism, and somatic complaints. Scores on the remaining factors (sleep disturbance, attention deficit, impulsivity, hyperactivity, oppositional defiant disorder, conduct disorder, and anxiety) increased explained variance by less than 2%. Findings suggest that SCT is not simply sluggish cognitive tempo, as the name implies, and is a complex construct with behavioral, affective, emotional, cognitive, and somatic components and associations. Given that 49% of children with autism had SCT, SCT symptoms should be considered in all children being evaluated for autism, as well as for ADHD-C and ADHD-I (with SCT percentages of 31% and 40%). Assessing and treating SCT is especially important because of its association with impairment.

Examining the Role of Attention Deficits in the Social Problems and Withdrawn Behavior of Children With Sluggish Cognitive Tempo Symptoms

Previous studies have found that sluggish cognitive tempo (SCT) symptoms are often associated with social problems and withdrawn behavior. However, the possible neuropsychological mechanism underlying this relationship remains unclear. Some studies have also found that SCT symptoms are related to deficits in sustained attention and selective attention. However, no study has examined whether attention deficits are related to social problems and withdrawn behavior in children with SCT. This study was the first to examine the neuropsychological correlates of social problems and withdrawn behavior among children with SCT symptoms. The results showed that sustained attention measure (omission) predicted the severity of social problems and withdrawn behavior in children with SCT even after controlling for symptoms of attention-deficit hyperactivity disorder. Selective attention measure (response latency mean) was also found to predict the severity of social problems. These results suggest that the social problems commonly exhibited by children with SCT are related to deficits in sustained attention and attentional control. Thus, our results provide an initial support to the link between attention deficits and social problems among children with SCT.

Neuro-physiological correlates of sluggish cognitive tempo (SCT) symptoms in school-aged children

This study was the first to examine the relationship between neurophysiological abnormalities and symptoms of sluggish cognitive tempo (SCT) in children. Thirty children aged 6-12 years were recruited. Their heart rate variability (HRV) was measured under resting and warning signal conditions. At rest, the children's SCT symptoms were found to be positively associated with their HRV (indicated by the standard deviation of the Poincaré plot along the line of identity in normalized units, SD2 nu). SCT symptoms were also positively associated with a change in SD2 nu between the resting and warning signal conditions. When controlling for symptoms of attention deficit hyperactivity disorder, the children's SCT symptoms were significantly predicted by their resting SD2 nu and by changes in SD2 nu and the percentage of successive RR intervals that differ by more than 50 ms (pNN50) between the resting and warning signal conditions. These findings suggest that the readiness and regulation of the autonomic nervous system may contribute to symptoms of SCT. Specifically, disturbances in the internal neurophysiological system may explain the difficulties experienced by children when exposed to environmental stimulation. These initial data support the hypothesis that SCT results from deficiencies in arousal.

Sluggish cognitive tempo: An examination of clinical correlates for adults with autism

LAY ABSTRACT

Adults with autism spectrum disorder often experience a range of co-occurring mental health problems such as attention-deficit/hyperactivity-disorder, as well as difficulties with executive function. Sluggish cognitive tempo, a cluster of behaviors including slow processing, daydreaming, and mental fogginess, has been shown to be associated with attention-deficit/hyperactivity-disorder, and limited research has suggested that individuals with autism spectrum disorder may experience sluggish cognitive tempo. We examined co-occurring mental health problems and executive function in 57 young adults with autism spectrum disorder, aged 16-25 years to better understand sluggish cognitive tempo in autism spectrum disorder. Parents of the young adults answered questions about their children's sluggish cognitive tempo, attention-deficit/hyperactivity-disorder, depression, and anxiety symptoms, and the young adults completed tests of their executive function. Results demonstrated that nearly one-third of the sample exhibited clinically impairing levels of sluggish cognitive tempo. Although sluggish cognitive tempo and attention-deficit/hyperactivity-disorder symptoms were related, our findings suggest they are not the same constructs. Increased sluggish cognitive tempo is related to more difficulties with executive function and increased depression, but not anxiety symptoms. Results demonstrate that sluggish cognitive tempo may pose heightened difficulties for adults with autism spectrum disorder, making it an important construct to continue studying. Considerations for assessment and long-term impacts of sluggish cognitive tempo for adults with autism spectrum disorder are discussed.

Sleep, Internalizing Problems, and Social Withdrawal: Unique Associations in Clinic-Referred Youth With Elevated Sluggish Cognitive Tempo Symptoms

Objective: We compared clinic-referred youth with ADHD + sluggish cognitive tempo (SCT; n = 34), ADHD Only (n = 108), and SCT Only (n = 22) on demographics, co-occurring symptomatology, comorbid diagnoses, and social functioning. Method: In total, 164 youth (age = 6-17 years, M = 9.97) and their parent(s) presented to an outpatient clinic for a psychoeducational assessment. Between-group analyses and regressions were used to examine study variables. Results: SCT groups were older and exhibited more parent-reported internalizing problems, externalizing problems, sleep problems, and social withdrawal on the Child Behavior Checklist. No significant differences emerged between groups on the Teacher Report Form. Regression analyses involving multiple covariates revealed that SCT symptoms were uniquely related to social withdrawal but not general social problems. Conclusion: Based on parent report, SCT symptoms have a unique relationship with internalizing problems, sleep problems, and social withdrawal. Future research should explore correlates of SCT in youth using multiple informants.

Prevalence, Patterns, and Predictors of Sleep Problems and Daytime Sleepiness in Young Adolescents With ADHD

Objective: The primary objective of this study was to evaluate the prevalence of multiple types of sleep problems in young adolescents with ADHD. Method: Adolescents comprehensively diagnosed with ADHD (N = 262) and their caregivers completed well-validated measures of sleep problems and daytime sleepiness. Participants also completed measures related to medication use, comorbidities, and other factors that could predict sleep problems. Results: Daytime sleepiness was by far the most common sleep problem, with 37% of adolescents meeting the clinical threshold according to parent report and 42% according to adolescent report. In contrast, prevalence rates for specific nighttime sleep problems ranged from 1.5% to 7.6%. Time spent in bed, bedtime resistance, ADHD inattentive symptoms, and Sluggish Cognitive Tempo (SCT) symptoms were significant in the final model predicting daytime sleepiness. Conclusion: Adolescents with ADHD commonly experience problems with daytime sleepiness that may significantly affect their functioning, but this may not be directly attributable to specific sleep problems.

What cognitive processes are "sluggish" in sluggish cognitive tempo?

OBJECTIVE

Sluggish cognitive tempo refers to a constellation of symptoms that include slowed behavior/thinking, reduced alertness, and getting lost in one's thoughts. Despite the moniker "sluggish cognitive tempo," the evidence is mixed regarding the extent to which it is associated globally with slowed (sluggish) mental (cognitive) information processing speed (tempo).

METHOD

A well-characterized clinical sample of 132 children ages 8-13 years (M = 10.34, SD = 1.51; 47 girls; 67% White/non-Hispanic) were administered multiple, counterbalanced neurocognitive tests and assessed for sluggish cognitive tempo symptoms via multiple-informant reports.

RESULTS

Bayesian linear regressions revealed significant evidence against associations between sluggish cognitive tempo and computationally modeled processing speed (BF01 > 3.70), and significant evidence for associations with slower working memory manipulation speed. These findings were consistent across parent and teacher models, with and without control for attention-deficit/hyperactivity disorder inattentive symptoms and IQ. There was also significant evidence linking faster inhibition speed with higher parent-reported sluggish cognitive tempo symptoms.

CONCLUSIONS

These findings provide strong evidence against characterizing children with sluggish cognitive tempo symptoms as possessing a globally sluggish cognitive tempo. Instead, these symptoms appear to be related, to a significant extent, to executive dysfunction characterized by working memory systems that are too slow and inhibition systems that are too fast. Behaviorally, these findings suggest that requiring extra time to rearrange the active contents of working memory delays responding, whereas an overactive inhibition system likely terminates thoughts too quickly and therefore prevents intended behaviors from starting or completing, thereby giving the appearance that children are absent-minded or failing to act when expected. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Sluggish Cognitive Tempo and ADHD Symptoms in a Nationally Representative Sample of U.S. Children: Differentiation Using Categorical and Dimensional Approaches

A nationally representative sample of U.S. children was used to determine the empirical and clinical differentiation of sluggish cognitive tempo (SCT) and attention-deficit/hyperactivity disorder (ADHD) symptoms using both categorical and dimensional approaches. Mothers of children (N = 2,056, M± SD_age = 8.49 ± 2.15 years, 49.3% girls) completed measures of SCT, ADHD, oppositional defiant disorder (ODD), anxiety, depression, sleep difficulties, daily life executive functioning, conflicted shyness, friendship difficulties, and social and academic impairment. Scores greater than the top 5% on SCT and ADHD measures were used to create SCT-only (n = 53, 2.58%), ADHD-only (n = 93, 4.52%), SCT+ADHD (n = 49, 2.38%), and comparison (n = 1,861, 90.52%) groups. Fifty-two percent of the SCT group did not qualify for the ADHD group, whereas 65% of the ADHD group did not qualify for the SCT group. The SCT-only group had higher levels of anxiety, depression, conflicted shyness, and sleep difficulties than the ADHD-only group. In contrast, the ADHD-only group had greater executive functioning deficits and higher ODD than the SCT-only group. SCT-only and ADHD-only groups showed similar levels of friendship, social, and academic impairment. Similar findings emerged when using structural regression analyses to determine the unique clinical correlates of SCT and ADHD dimensions. This is only the second study to examine the distinction of clinically-elevated SCT from ADHD in a national sample of children and extends previous findings to a broader array of functional outcomes. Normative information on the SCT scale also provides a validated rating scale to advance research and clinical care.

Shorter REM latency in children with attention-deficit/hyperactivity disorder

The discrepancies in prior research about the actual sleep problems underlying attention-deficit/hyperactivity disorder (ADHD) demand more studies of children with this disorder. This study aimed to compare the subjective and objective sleep characteristics of 20 children with ADHD (DSM-IV criteria) and 20 typically developing children (aged 7-11 years). We assessed the children using sleep questionnaires and polysomnography recordings and analysed differences between the two groups using two-tailed Mann-Whitney U exact tests and Rosenthal's r as effect size measure. We also assessed associations between sleep measures and psychopathology using Spearman's correlation coefficients. No significant difference was found between the groups in almost any objective sleep variable, except for shorter REM latency in the ADHD group. Children with ADHD also showed significantly higher levels of daytime sleepiness and greater general sleep problems than control children, as reported by their parents, after discarding the primary sleep problems commonly associated with ADHD. Significant correlations were found between psychopathology and sleep measures. Our findings might support the link between narcolepsy-like sleep phenotype and ADHD. However, longitudinal research combining objective and subjective assessments should further explore the involvement of other variables, such as ADHD subtypes, medication, and comorbid symptoms in this relationship.

Clinical correlates of sluggish cognitive tempo in adolescents with autism spectrum disorder

Adolescents with autism spectrum disorder frequently experience social communication difficulties, executive functioning deficits, and anxiety and depressive symptoms, which are similar to the symptoms and correlates of sluggish cognitive tempo. Although sluggish cognitive tempo is related to, but distinct from, the inattentive and hyperactive-impulsive symptoms of attention-deficit/hyperactivity disorder that commonly co-occur with autism spectrum disorder, few studies have examined sluggish cognitive tempo in autism spectrum disorder. We examined whether sluggish cognitive tempo and attention-deficit/hyperactivity disorder were differentially associated with autism symptomatology, daily life executive functioning, and internalizing and externalizing symptoms in 51 adolescents (ages 13-18 years) with autism spectrum disorder without intellectual disability. Regression analyses controlling for age and IQ showed that sluggish cognitive tempo symptoms, but not attention-deficit/hyperactivity disorder symptoms, were associated with increased autism symptomatology and internalizing symptoms. Attention-deficit/hyperactivity disorder symptoms, but not sluggish cognitive tempo symptoms, were associated with increased externalizing behaviors and behavior regulation deficits. Both sluggish cognitive tempo and attention-deficit/hyperactivity disorder were independently associated with increased metacognitive deficits. This study provides preliminary evidence that sluggish cognitive tempo symptoms are elevated in autism spectrum disorder and associated with key clinical correlates, with implications for the assessment and treatment in adolescents with autism spectrum disorder.

Advancing the study of sluggish cognitive tempo via DSM, RDoC, and hierarchical models of psychopathology

Sluggish cognitive tempo (SCT) is separable from attention-deficit/hyperactivity disorder (ADHD) and other psychopathologies, and growing evidence demonstrates SCT to be associated with impairment in both children and adults. However, it remains unclear how SCT should optimally be conceptualized. In this article, we argue that multiple models of psychopathology should be leveraged to make substantive advances to our understanding of SCT. Both categorical and dimensional approaches should be used, including the Diagnostic and Statistical Manual of Mental Disorders (DSM) nosology, the Research Domain Criteria (RDoC) initiative, and hierarchical models of psychopathology. Studies are needed to determine whether individuals categorized with SCT can be reliably identified and differentiated from individuals without SCT in pathophysiological, neuropsychological, behavioral, and daily life functioning. Studies are also needed to evaluate the validity and utility of SCT as a transdiagnostic and dimensional construct. In considering SCT as a dimensional and potentially transdiagnostic construct, we describe ways in which SCT might be examined within the RDoC framework, including negative valence systems, cognitive systems, and arousal/regulatory systems, as well as within hierarchical models of psychopathology. Conceptualizing SCT within both categorical and dimensional models of psychopathology will help to better understand the causes, developmental pathways, and clinical implications of SCT, both as a construct in its own right and also in relation to other psychopathologies.

Sluggish cognitive tempo: longitudinal stability and validity

Emerging research has identified sluggish cognitive tempo (SCT) as a construct separate from ADHD predominately inattentive presentation. The present study explores the longitudinal stability of SCT over a period of 7 years, specifically the independent effects of SCT on behavioural and academic outcomes concurrently over a 3-year period. A sample of 639 twins, aged 6-12 years, participating in the Western Reserve Reading and Math Project (WRRMP) were assessed at seven annual home visits. The WRRMP sample is an unselected sample of twins representative of the general population of typically developing school-age children. The current investigation will focus on parent and teacher reports which assess attention deficit hyperactive/impulsive disorder (ADHD) and standardized achievement measures which assess academic outcomes. Over periods longer than 1 or 2 years, SCT does not display good longitudinal stability (r < .60). SCT also does not have consistent significant independent effects on academic outcomes once the effects of ADHD were controlled for. Over a 7-year period, SCT does not demonstrate consistent longitudinal stability. SCT significantly predicts social problems, internalizing behaviours, and anxious/depressive behaviours after the effects of ADHD are controlled for. SCT has no significant independent effects on cognitive or educational outcomes after the effects of inattentive ADHD are controlled for.

Clinical differentiation of sluggish cognitive tempo and attention-deficit/hyperactivity disorder in children

This study (a) determined whether clinical elevations of sluggish cognitive tempo (SCT) and attention-deficit/hyperactivity disorder (ADHD) symptom distributions in a large community sample of children would allow for identifying SCT-only, ADHD-only, and SCT + ADHD clinical groups; (b) examined co-occurrence of clinically elevated SCT and ADHD; (c) evaluated whether these clinical groups differed in their gender distribution, co-occurring mental health symptoms, or impairment in academic and social functioning; and (d) explored patterns of independence and overlap when clinically elevated depressive symptoms were considered in tandem with SCT and ADHD. Participants were mothers, fathers, and teachers of 2,142 children (50.51% boys, ages 8-13 years) from 32 schools in Spain. All three groups of informants completed measures of SCT, ADHD, oppositional defiant disorder (ODD), anxiety, depression, shyness, social impairment, and academic impairment. Cut-off scores for the top 5% of the sample were used to create SCT-only, ADHD-only, SCT + ADHD, and comparison groups. Across informants, 4.97%-5.53% met criteria for clinically elevated ADHD-only, and 2.30%-2.80% met criteria for clinically elevated SCT-only; 27%-35% of the ADHD group also met the criteria for the SCT group, whereas 44%-54% of the SCT group met the criteria for the ADHD group (primarily based on inattentive symptoms). The ADHD-only group had higher ODD scores than the SCT-only group, whereas the SCT-only group generally had higher shyness and internalizing scores (particularly depression) than the ADHD-only group. Additional analyses that also included clinically elevated depression revealed that 28-46% of the children with elevated SCT had elevations in neither ADHD nor depression. This study moves the field toward examining both the empirical and clinical differentiation of SCT and ADHD. Findings are discussed regarding how SCT may fit in diagnostic nosologies and models of psychopathology. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Sluggish cognitive tempo in adults: Psychometric validation of the Adult Concentration Inventory

[Correction Notice: An Erratum for this article was reported in Vol 30(3) of Psychological Assessment (see record 2017-30273-001). In the article, the Table 1 item content was incorrectly ordered. The table, as well as text referencing Table 1 in the Results and Discussion, have been corrected in all versions of this article.] As interest in sluggish cognitive tempo (SCT) increases, a primary limitation for the field is the lack of a unified set of symptoms for assessing SCT. No existing SCT measure includes all items identified in a recent meta-analysis as optimal for distinguishing between SCT and attention-deficit/hyperactivity disorder (ADHD) inattention. This study evaluates a new self-report measure for assessing SCT in adulthood, the Adult Concentration Inventory (ACI), which was developed in response to the meta-analytic findings for assessing SCT. Using a large, multiuniversity sample (N = 3,172), we evaluated the convergent and discriminant validity and reliability of the ACI. We also evaluated the ACI measure of SCT in relation to self-reported demographic characteristics, daily life executive functioning, socioemotional adjustment (i.e., anxiety/depression, loneliness, emotion dysregulation, self-esteem), and functional impairment. Exploratory confirmatory factor analyses resulted in 10 ACI items demonstrating strong convergent and discriminant validity from both anxiety/depressive and ADHD inattentive symptom dimensions. SCT was moderately to-strongly correlated with daily life EF deficits, poorer socioemotional adjustment, and greater global functional impairment. Moreover, SCT remained uniquely associated in structural regression analyses with most of these external criterion domains above and beyond ADHD. Finally, when internalizing symptoms were also covaried, SCT, but not ADHD inattention, remained significantly associated with poorer socioemotional adjustment. These findings support the use of the ACI in future studies examining SCT in adulthood and make a major contribution in moving the field toward a unified set of SCT items that can be used across studies. (PsycINFO Database Record

Are sluggish cognitive tempo symptoms associated with executive functioning in preschoolers?

The aim of this study is to investigate whether sluggish cognitive tempo (SCT) symptoms are associated with neurocognitive task performance and ratings of real-world executive functioning (EF) in preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD). The associations between parent- and teacher-rated SCT symptoms and neuropsychological task performance and ratings of EF in 61 4-year-old preschool children (51 boys, 10 girls) with self-regulation difficulties were examined, with regression analyses controlling for the effects of ADHD inattention symptoms. In the study sample, higher teacher-rated SCT symptoms are significantly associated with poorer performance on tasks of visual-perceptual abilities, auditory and visual attention, sustained and selective attention, inhibitory control, pre-numerical/numerical concepts, and slower processing speed, but SCT symptoms are not significantly associated with working memory, attention shifting or cognitive flexibility when controlling for ADHD inattention. Higher parent-rated SCT symptoms are significantly associated with visual-perceptual abilities. ADHD inattention symptoms are more strongly associated than SCT with daily life EF ratings; neither parent- nor teacher-rated SCT symptoms are significantly associated with daily life ratings of inhibition, working memory, or planning/organization after controlling for ADHD inattention. This study suggests that SCT symptoms contribute to EF deficits at least on neurocognitive tasks assessing visual-perceptual/spatial abilities, attention to detail and processing speed, as observed in this sample of young children at risk for ADHD, and may be an important intervention target.

Sluggish cognitive tempo in children and adolescents with higher functioning autism spectrum disorders: Social impairments and internalizing symptoms

Sluggish cognitive tempo (SCT) was introduced in 1980s in the field of attention deficit hyperactivity disorder (ADHD). Studies indicate that symptoms of SCT are separate from symptoms of ADHD and independently associated with multiple domains of functioning in clinical groups and in typical development. We assessed whether similar pattern would apply to higher functioning autism spectrum disorders (ASD). Children with higher functioning ASD (N = 55; 5-15 years) were divided into the ASD+High SCT (n = 17), the ASD+Medium SCT (n = 18) and the ASD+Low SCT (n = 20) groups based on parent-rated daydreaming and slowness on the Five to Fifteen questionnaire (FTF). The groups were compared on SCT-related impairments found in previous studies: social skills, academic functioning, psychiatric symptoms, and processing speed. Assessment methods were the FTF, the Development and Well-Being Assessment, and the Coding subtest of the WISC-III. The ADHD symptoms were statistically controlled due to the overlap between SCT and ADHD. The ASD+High SCT and ASD+Medium SCT groups were significantly more likely to have the most pronounced social impairments, and the ASD+High SCT group had significantly higher rate of internalizing disorders compared to the ASD+Low SCT group. Our results suggest that children with higher functioning ASD and high or medium levels of SCT symptoms could be at higher risk for psychosocial impairments than children with higher functioning ASD with low levels of SCT symptoms. Co-occurring ADHD symptoms do not explain the finding. Recognizing SCT symptoms in higher functioning ASD would be important to targeting preventive support.

Can Sluggish Cognitive Tempo Be Distinguished From ADHD Inattention in Very Young Children? Evidence From a Sample of Korean Preschool Children

OBJECTIVE

This study evaluated whether sluggish cognitive tempo (SCT) is separable from ADHD-inattention (IN) and uniquely associated with internalizing dimensions in preschool children in South Korea.

METHOD

Mothers of 172 preschool children (ages 4-6 years; 52% girls) rated children's SCT, ADHD-IN, ADHD-hyperactivity/impulsivity (HI), oppositional defiant disorder (ODD), aggression, emotional reactivity, anxiety/depression, somatic complaints, withdrawal, and sleep problems.

RESULTS

Eight of 10 SCT symptoms showed convergent and discriminant validity with ADHD-IN. ADHD-IN remained significantly positively associated with ADHD-HI, ODD, and aggressive behavior after controlling for SCT, whereas SCT was no longer positively associated with these externalizing behaviors after controlling for ADHD-IN. Both SCT and ADHD-IN were uniquely associated with greater emotionally reactivity, anxiety/depression, and withdrawal. Only SCT was uniquely associated with somatic complaints, and only ADHD-IN was uniquely associated with sleep problems.

CONCLUSION

Findings replicate results with children and adolescents, thus expanding evidence for the validity of SCT in early development.

Effect of sleep extension on sluggish cognitive tempo symptoms and driving behavior in adolescents with chronic short sleep

OBJECTIVE/BACKGROUND

Few adolescents report obtaining adequate amounts of sleep. Correlational studies have linked adolescent short sleep with driving crashes and sluggish cognitive tempo (SCT), a cluster of symptoms that include sluggishness and low persistence that are related to but distinct from inattention and sleepiness. The relationship between SCT and driving is understudied, and no study has experimentally examined the relationship between SCT and sleep. We examined the relationship between SCT and driving problems in a sample of chronically short-sleeping adolescents. We also examined whether experimentally extending sleep improved SCT and driving behaviors.

PARTICIPANTS/METHODS

Licensed 16- to 18-year-old adolescents who regularly obtained five to seven hours of sleep completed a five-week at-home experimental protocol: a baseline week to determine typical sleep (TYP), followed in a counterbalanced order by two-week spans in which school-night bedtimes and rise times were (a) matched to TYP or (b) modified to extend (EXT) time in bed by 1.5 h/night. Sleep was monitored by actigraphy. Self- and parent-reported SCT and inattention and self-reported driving problems were recorded at baseline and following each condition. Of the 38 eligible participants who completed the baseline session, 24 completed all five weeks of the protocol.

RESULTS

After controlling for inattention, only parent-reported SCT was significantly positively associated with self-reported purposeful driving violations at baseline. Adolescents reported lesser SCT during EXT than during TYP. Further, after controlling for inattention, participants who reported improvement in SCT demonstrated fewer driving problems during EXT than during TYP.

CONCLUSIONS

Preliminary findings suggest that extending sleep in short-sleeping adolescents may help alleviate SCT symptoms and improve driving.

Evaluating the Structure of Sluggish Cognitive Tempo Using Confirmatory Factor Analytic and Bifactor Modeling With Parent and Youth Ratings

The primary goals of this study were to evaluate the dimensionality of the Penny et al. Sluggish Cognitive Tempo Scale and to compare model fits for parent- and youth self-report versions. Participants were 262 young adolescents (ages 10-15) comprehensively diagnosed with attention-deficit/hyperactivity disorder. Both confirmatory factor analysis (CFA) and bifactor modeling were used to determine if the proposed three-factor structure previously identified through exploratory factor analysis could be confirmed. Results showed that although the three-factor CFA had better fit statistics than a one- or two-factor CFA, the bifactor model was the best-fitting model for both parent report and self-report. This implies that Sluggish Cognitive Tempo Scale is best conceptualized as having an underlying general factor, with three specific factors that may represent different etiologies. Importantly, results also showed low-to-moderate correlations between raters and equivalent or better fit statistics for self-report in comparison with parent report.