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

Research supports the distinctness of sluggish cognitive tempo (SCT) (e.g., mental confusion and slowed behavior/thinking) from other psychopathologies. However, the relation between SCT and sleep functioning has not been adequately studied. We examined the association between SCT and sleep functioning in 325 children (62% male) ages 6–10 years referred to a pulmonary-based, accredited Sleep Disorders Center. Correlations between caregiver ratings of SCT, other psychopathologies (i.e., inattention/hyperactivity, oppositionality, depression, anxiety), sleep functioning (both behavioral and organic symptoms), as well as sleep disorder diagnoses, were examined. Unique effects of SCT and other psychopathologies on sleep problem severity controlling for child demographics were assessed using regressions. Regression analyses were also conducted to examine the unique effects of SCT on impairment (i.e., academic difficulties, parenting stress, and other psychopathologies) controlling for child demographics, sleep problem severity, and other psychopathology symptoms. SCT was weakly to moderately correlated with most measures of sleep (rs = .07–.39) and moderately to strongly correlated with measures of daytime sleepiness (rs = .33 and .53). In the regression analyses, SCT was uniquely associated with greater sleep functioning severity and impairment in academic functioning. SCT was also uniquely associated with higher levels of depression and inattention/hyperactivity, but not anxiety, and negatively associated with oppositionality. Finally, SCT symptoms were uniquely associated with greater parent-child dysfunctional interaction. Findings demonstrate that SCT is related to, but not redundant with, sleep problems and daytime sleepiness specifically. Further, SCT remained associated with several domains of functional impairment in sleep-disordered children after controlling for clinically-relevant variables, highlighting the potential value in assessing SCT symptoms in children with sleep problems.