{"p"=>{"__content__"=>"Cognitive Disengagement Syndrome (CDS) refers to symptoms of fogginess, daydreaming, blank staring, and slowed behaviour. Growing evidence suggests that CDS reflects a transdiagnostic construct. This study aimed to examine (1) associations between age, sex, and CDS severity; (2) differences in CDS across Attention-Deficit/Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), and internalizing disorders; and (3) associations between CDS and quality of life, as assessed by the KIDSCREEN-27. CDS was assessed in 958 clinically referred children and adolescents (mean age = 10.7 ± 2.8 years; 36.3% female) with a primary diagnosis of ADHD ( = 353), ASD ( = 494), or internalizing disorders ( = 111). Four Child Behaviour Checklist (CBCL) items (13, 17, 80, 102) were used to operationalize CDS. Analyses included ANOVAs, MANOVAs, and multiple regression analyses in the full sample and a subsample without comorbidities. CDS levels didn’t differ by sex, whereas adolescents (12—17 years) showed higher CDS levels than children (6—11 years). Across diagnostic groups, ASD ( = 2.6, SD = 1.8) and internalizing disorders ( = 2.6, SD = 1.9) displayed higher CDS scores than ADHD ( = 1.8, SD = 1.6;  < .001). These findings remained significant in the subsamples without comorbidities ( < .001). Multiple regression analyses indicated that higher CDS scores were significantly associated with lower quality of life ( = -2.20,  < .001), independent of diagnostic group, sex, and age, without significant interaction between CDS and diagnosis. Correlational analyses indicated stronger associations between CDS with autistic ( = .25-.36;  < .05) and affective CBCL symptom dimensions ( = .19-.36;  < .05) dimensions than with ADHD symptoms. CDS appears to represent a clinically relevant transdiagnostic construct. Its strong expression in ASD suggests that it captures disengagement mechanisms beyond current nosological frameworks.", "i"=>[{"__content__"=>"n"}, {"__content__"=>"n"}, {"__content__"=>"n"}, {"__content__"=>"M"}, {"__content__"=>"M"}, {"__content__"=>"M"}, {"__content__"=>"p"}, {"__content__"=>"p"}, {"__content__"=>"B"}, {"__content__"=>"p"}, {"__content__"=>"r"}, {"__content__"=>"p"}, {"__content__"=>"r"}, {"__content__"=>"p"}]}}