Cognitive disengagement syndrome has a contributory role in the association between inattention and eveningness chronotype in children and adolescents with ADHD.

Abstract

This study aimed to examine the associations between cognitive disengagement syndrome (CDS), chronotype, and Attention-Deficit/ Hyperactivity Disorder (ADHD) symptomatology in children and adolescents, and to identify whether different ADHD presentations show distinct profiles in terms of CDS severity and chronotype preference. The sample included 99 children and adolescents aged 8 to 17 years, evenly divided into three groups: ADHD-inattentive presentation (ADHD-I; n = 33), ADHD-combined presentation (n = 33), and typically developing controls (TDC; n = 33). The assessment was conducted using the Schedule for Affective Disorders and Schizophrenia for School-Age Children. Turgay DSM-IV-Based Disruptive Disorders Rating Scale, Sluggish Cognitive Tempo Scale, Strength and Difficulties Questionnaire and Children's Chronotype Questionnaire were completed by mothers. There were significant group differences in CDS (F = 3.762, p = 0.027) and chronotype (F = 4.709, p = 0.011) scores. Post hoc analysis showed that the ADHD-I group had significantly higher eveningness scores compared to the TDCs (p = 0.014). CDS symptoms, particularly daytime sleepiness, were positively correlated with eveningness (r = 0.461, p < 0.01). Linear regression analysis revealed that inattention was significantly associated with eveningness chronotype (B = 0.20, p = 0.02), and CDS symptoms also emerged as a significant predictor (B = 0.20, p = 0.003). Daytime sleepiness partially mediated the association between inattention and eveningness symptoms (B = 0.09, p < 0.01), even after controlling for age and gender. The findings suggest that CDS symptoms, particularly daytime sleepiness, may play a contributory role in the association between inattention and eveningness chronotype in youth with ADHD. Incorporating chronotype and CDS features into clinical assessment may enhance understanding of attentional profiles and guide targeted behavioral or chronobiological interventions.