Recent studies indicate that the symptoms of<unk>  in children form two dimensions: daydreamy-spacey and<unk> -lethargic, and that the former are more distinctive of the disorder from ADHD than the latter. This same pattern was recently found in the first study of adults with<unk>  by Barkley and also in more recent studies of college students. These studies indicated that<unk>  is probably not a subtype of ADHD but a distinct disorder from it. Yet it is one that overlaps with ADHD in 30–50% of cases of each disorder, suggesting a pattern of comorbidity between two related disorders rather than subtypes of the same disorder. Nevertheless,<unk>  is strongly correlated with ADHD inattentive and combined subtypes. According to a Norwegian study, "SCT correlated significantly with inattentiveness, regardless of the subtype of ADHD."
Sluggish cognitive tempo
Compulsive behavior
Social-emotional agnosia
Psychological resistance
Callous and unemotional traits
Musical anhedonia
Emotional lability
Communication apprehension