Daydreaming, Drifting Minds and Words: New Study Probes the Language Link in Children with ADHD

For decades, clinicians have noticed that a subgroup of children with attention-deficit/hyperactivity disorder seems different from the rest: instead of bouncing off walls, these children drift away, stare out of windows, and sink into daydreams. The cluster of traits behind this picture, once awkwardly called sluggish cognitive tempo, is now formally known as cognitive disengagement syndrome, or CDS. A new study from Denmark, published in Frontiers in Psychiatry, is the first to ask whether this dreamy, under-aroused syndrome is linked to the language difficulties so common in children with ADHD, and the answer turns out to be more nuanced, and more instructive, than a simple yes or no.

CDS describes a constellation of symptoms that includes excessive daydreaming, slowed processing speed, low energy, drowsiness, and a general sense of mental under-arousal. It is strikingly common in ADHD: between 25 and 40 percent of children with the disorder show elevated CDS symptoms. Yet research over the past decade has increasingly argued that CDS is a distinct construct, not merely a passive form of inattention. Where ADHD inattention is often characterized by external distractibility, a child pulled off task by noises or movements in the room, CDS appears to involve internal distractibility, a mind that wanders inward and becomes lost in its own thoughts. Understanding what separates the two, and what each contributes to real-world functioning, has become one of the livelier debates in child psychiatry.

The stakes are high because children with ADHD already carry a heavy burden of language problems. Roughly 40 percent of children and adolescents with ADHD meet criteria for a language disorder, and at group level they show elevated rates of pragmatic language difficulties, trouble with the social side of communication, such as initiating conversations, reading contextual cues, and interpreting nonverbal signals. These language problems are not cosmetic. They are associated with the social challenges and academic underachievement that so often define life with ADHD. What has remained unclear is which children with ADHD are most at risk, and what underlying traits drive the language difficulties. CDS seemed a plausible candidate: a syndrome defined by mental disengagement could plausibly reduce how efficiently a child encodes, organizes, and retrieves linguistic information.

Previous evidence was thin but suggestive. Studies by Russell Barkley and later by G. Leonard Burns and Stephen Becker found that the prevalence of language delay was highest in children showing both ADHD and CDS symptoms, compared with children showing only one of the two. A single study examining language directly found that children with heightened CDS symptoms had more parent-reported social pragmatic difficulties than children with low CDS, with a medium effect size. Similar findings emerged in autistic children, where CDS explained social pragmatic communication difficulties above and beyond core characteristics of autism. What no one had done, until now, was test the CDS-language link specifically in children with ADHD.

The Danish team, led by Ida Jepsen of Aarhus University with colleagues from Aarhus, Copenhagen, Aalborg, and Agder universities, drew on a larger research project on ADHD and language, with data collected between May 2018 and January 2022. The final sample comprised 45 children with ADHD, recruited from a specialist clinic at a Danish public child and adolescent psychiatric hospital, and 38 neurotypical children recruited from schools in the same region. All children were between 7 and 11 years old, had Danish as a first language, and met strict exclusion criteria, no history of autism, epilepsy, or brain injury, an IQ of at least 70, and adequate sensory and motor function to complete the tasks. Children on psychotropic medication had it discontinued at least 24 hours before assessment.

The study’s methodological strength lies in measuring three distinct dimensions of language rather than treating language as a single monolithic skill. Narrative coherence was assessed with the classic wordless picture book Frog, Where Are You?, with children telling the story in their own words and blind coders rating whether they captured the beginning, middle, and end. Core language, the formal, rule-based machinery of grammar and syntax, was measured with subtests from the Clinical Evaluation of Language Fundamentals-4. Pragmatic language was assessed through the parent-report Children’s Communication Checklist-2, covering inappropriate initiations, stereotypical language use, use of conversational context, and nonverbal communication. CDS itself was measured with three parent-rated items from the SWAN scale capturing daydreaming, drowsiness, and apathy, and the ratings showed good agreement with independent teacher reports.

The initial results looked striking. After adjusting for age and sex, CDS was significantly associated with pragmatic language in children with ADHD, with a large effect: the more a child daydreamed and drifted, the worse the parent-rated pragmatic communication (β = -0.51, p = .001). In the neurotypical children, the pattern differed: CDS was instead linked to core language, with a medium effect (β = -0.34, p = .04). The group difference on the pragmatic language link was statistically significant (χ²(1) = 4.44, p = .04), suggesting that the CDS-pragmatics relationship was genuinely stronger in ADHD. Neither group showed any association between CDS and narrative coherence, so the ability to tell a coherent story appeared untouched by the dreamy syndrome.

Then came the twist. Because CDS and ADHD inattention overlap substantially, the researchers ran a sensitivity analysis adding inattention as a covariate. The headline findings dissolved. The CDS-pragmatic language association in the ADHD group was no longer significant (β = -0.26, p = .08), the CDS-core language association in neurotypical children vanished, and the between-group difference on pragmatics ceased to be significant. In other words, the apparent CDS-language link may largely reflect variance shared with ordinary inattention, which is itself independently associated with language problems. The authors are careful to note the flip side: because CDS and inattention share so much variance, statistically controlling for inattention may strip away variance that is genuinely part of the CDS construct, a risk of overadjustment analogous to the long-standing debate about controlling for IQ in ADHD research. Previous studies of CDS and language did not control for inattention at all, so there is currently no way to know whether their findings would have survived the same test.

The study is explicitly exploratory and carries real limitations that the authors acknowledge candidly. The sample is modest, limiting power to detect small effects or subtle group differences, and the design is cross-sectional, so causal direction cannot be established. All three key constructs, CDS, inattention, and pragmatic language, were rated by parents, raising the possibility of same-rater bias, although teacher ratings collected for a subset of children showed acceptable agreement; pandemic disruptions meant teacher questionnaires could not serve as full independent measures. The ADHD group contained far more boys than girls, and internalizing symptoms such as anxiety, known to relate to both CDS and language, were not controlled. Given that this is, to the authors’ knowledge, the only study to date on CDS and language in children with ADHD, replication in larger, independent samples is essential.

Even so, the clinical implications of confirming such a link could be substantial. Pragmatic language difficulties appear to worsen the social impairments seen in children with ADHD, and language problems in this population remain under-identified. If CDS were shown to specifically predict pragmatic problems, the presence of dreamy, disengaged symptoms during a clinical assessment might prompt clinicians to screen for social communication difficulties, and vice versa. Support programs targeting CDS or inattention might then be paired with social communication interventions. The Danish team proposes that future work use structural equation modelling to establish the discriminant validity of CDS and inattention and quantify how much unique variance each contributes to pragmatic language. Longitudinal designs tracking language development over time, and multi-informant or performance-based measures rather than parent reports alone, would help determine whether the drifting, daydreaming mind carries its own linguistic signature, or whether what we are seeing is simply inattention wearing a different face.

Subject of Research: The association between cognitive disengagement syndrome and language abilities in children with and without ADHD

Article Title: The association between cognitive disengagement syndrome and language in children with attention-deficit/hyperactivity disorder

Article References: Jepsen, I., Brynskov, C., Rask, C. U., de López, K. J., Thomsen, P. H., & Lambek, R. (2026). The association between cognitive disengagement syndrome and language in children with attention-deficit/hyperactivity disorder. Frontiers in Psychiatry, 17, Article 1965712. https://doi.org/10.3389/fpsyt.2026.1965712

Image Credits: AI Generated

DOI: 10.3389/fpsyt.2026.1965712

Keywords: ADHD, cognitive disengagement syndrome, pragmatic language, inattention, children, language disorder, narrative coherence, core language, parent ratings, child psychiatry, social communication, cross-sectional study