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.