Cognitive disengagement syndrome
Symptoms often manifest in difficulties with staring, mind blanking, absent-mindedness, mental confusion and maladaptive mind-wandering alongside delayed, sedentary or slow motor movements.
CDS independently has a negative impact on functioning (such as a diminished quality of life,[9] increased stress and suicidal behaviour,[10] as well as lower educational attainment and socioeconomic status[11]).
The terms concentration deficit disorder (CDD) or cognitive disengagement syndrome (CDS) have recently been preferred to SCT because they better and more accurately explain the condition and thus eliminate confusion.
In contrast, people with ADHD have more difficulties with persistence of attention and action toward goals coupled with impaired resistance to responding to distractions.
[29] A key behavioral characteristic of those with CDS symptoms is that they are more likely to appear to be lacking motivation and may even have an unusually higher frequency of daytime sleepiness.
[18] The executive system of the human brain provides for the cross-temporal organization of behavior towards goals and the future and coordinates actions and strategies for everyday goal-directed tasks.
Essentially, this system permits humans to self-regulate their behavior so as to sustain action and problem solving toward goals specifically and the future more generally.
Dysexecutive syndrome is defined as a "cluster of impairments generally associated with damage to the frontal lobes of the brain" which includes "difficulties with high-level tasks such as planning, organising, initiating, monitoring and adapting behaviour".
[36] Such executive deficits pose serious problems for a person's ability to engage in self-regulation over time to attain their goals and anticipate and prepare for the future.
Adele Diamond postulated that the core cognitive deficit of those with ADHD-I is working memory, or, as she coined in a paper on the subject, "childhood-onset dysexecutive syndrome".
[37] However, two more recent studies by Barkley found that while children and adults with CDS had some deficits in executive functions (EF) in everyday life activities, they were primarily of far less magnitude and largely centered around problems with self-organization and problem-solving.
However, symptoms of CDS seem to indicate that the posterior attention networks may be more involved here than the prefrontal cortex region of the brain and difficulties with working memory so prominent in ADHD.
High rates of CDS were observed in children who had prenatal alcohol exposure and in survivors of acute lymphoblastic leukemia, where they were associated with cognitive late effects.
[41][42][43] CDS is included, with its previous name of sluggish cognitive tempo, as a diagnostic descriptor in the current International Classification of Diseases (ICD) released in 2022 under the World Health Organization (WHO).
Initial drug studies were done only with the ADHD medication methylphenidate, and even then only with children who were diagnosed as ADD without hyperactivity (using DSM-III criteria) and not specifically for CDS.
The research seems to have found that most children with ADD (attention deficit disorder) with Hyperactivity (currently ADHD combined presentation) responded well at medium-to-high doses.
[50] However, one study and a retrospective analysis of medical histories found that the presence or absence of CDS symptoms made no difference in response to methylphenidate in children with ADHD-I.
Atomoxetine may be used to treat CDS,[19] as multiple randomised controlled clinical trials (RCTs) have found that it is an effective treatment.
[52][53][54][55] Only one study has investigated the use of behavior modification methods at home and school for children with predominantly CDS symptoms and it found good success.
[18] However, unlike ADHD, there are no longitudinal studies of children with CDS that can shed light on the developmental course and adolescent or adult outcomes of these individuals.
Researchers exploring this subtype created rating scales for children which included questions regarding symptoms such as short attention span, distractibility, drowsiness, and passivity.
[68][69] Problematic with the paper is that it dismissed ADHD as a nonexistent disorder (despite it having several thousand research studies by then) and preferred the term PVD for this CDS-like symptom complex.
[66] Significant skepticism has been raised within the medical and scientific communities as to whether CDS, currently considered a "symptom cluster," actually exists as a distinct disorder.
[57] Allen Frances, emeritus professor of psychiatry at Duke University, argues: "We're seeing a fad in evolution: Just as ADHD has been the diagnosis du jour for 15 years or so, this is the beginning of another.
"[57] UCLA researcher and Journal of Abnormal Child Psychology editorial board member Steve S. Lee expresses concern that based on CDS's close relationship to ADHD, a pattern of overdiagnosis of the latter has "already grown to encompass too many children with common youthful behavior, or whose problems are derived not from a neurological disorder but from inadequate sleep, a different learning disability or other sources."
"[57] Adding to the controversy are potential conflicts of interest among the condition's proponents, including the funding of prominent CDS researchers' work by the global pharmaceutical company Eli Lilly.
