Neurodevelopmental and psychiatric issues in Down’s syndrome

Abstract

Down's syndrome (DS) is the most frequent genetic cause of intellectual disability and patients with DS show significant psychopathology (18-23%). Moreover, individuals with DS often show a cognitive decline associated with ageing characterized by a deterioration in memory, language and cognitive functioning. According to these relevant findings, an overview is presented of state-of-the-art knowledge of the neurocognitive, neurobiological and psychopathological profile, assessment and treatment of patients with DS. The linguistic characteristics of DS develop differently along distinct developmental trajectories. Thus, for example, morphosyntax deficit, especially in production, is more evident in adolescence than in early childhood and lexicon is usually better preserved in all ages (at least in comprehension). So far, rehabilitation is the only effective approach for improving cognitive and linguistic abilities. However, ongoing preliminary reports on other approaches such as transmagnetic stimulation or drugs suggest alternative or integrative treatment for the future. Individuals with DS show typical organization of brain structures related to some cognitive abilities, such as reduced volume in frontal and prefrontal areas, which is related to poor executive and linguistic abilities. They also frequently show psychiatric disorders such as externalizing disorders as well as depression, anxiety and obsessive-compulsive disorder. Nevertheless, as for other genetic syndrome with intellectual disability, there is a significant lack of research specifically focused on treatments of psychiatric and behavioural problems in DS. This is true both for psychosocial and for pharmacological interventions.

Psychopathology in Down Syndrome

“…DS exhibits distinctive neurodevelopmental, neurocognitive, and psychopathological patterns when compared to other genetic syndromes leading to ID, albeit higher than the general population [3]. People with ID often have more behavioral, emotional, and psychiatric problems than the general population [2].…”

“…These neuroanatomical diferences, although not speciic to autism and DS, may relect changing functional organization paterns that are common to both [3,56]. Cerebellum and brainstem white maters have increased volumes in individuals with autism along with DS in comparison to those without autism.…”

“…However, psychopathology is less frequent in DS compared to other children with intellectual disability [3]. The prevalence of depression in DS is 11%; DS is also a risk factor for developing depression [38,39].…”

“…The incidence of DS is about 1-1.5 of every 1000 live births. DS is the most frequent genetic cause of mental are more likely to have externalizing behaviors than their siblings and peers, including hyperactivity, impulsivity, inatention, tantrums, agitation, stubbornness, disruptiveness/argumentativeness, oppositionality, repetitive movements, sensory dysregulation, and speech problems despite being recognized as friendly, easygoing, good tempered, afectionate, and sympathetic individuals [3,5,6]. The rate of severe behavior disorder in children with DS is reported as 23% [7].…”

“…These rates may be low because it is diicult to assess the obsessions and compulsions in individuals with cognitive impairment. As for OCD, there is a lower prevalence of schizophrenia and bipolar disorder in individuals with DS [3]. In latest studies, the co-occurrence of DS and autism spectrum disorders (ASD) has increased ratio; approximately 6-10% of children have comorbid ASD [5].…”