Association between adaptive behaviour and age in adults with Down syndrome without dementia: examining the range and severity of adaptive behaviour problems

Symptoms and age of prodromal Alzheimer's disease in Down syndrome: a systematic review and meta-analysis

The diagnostic criteria for adult-onset Alzheimer's disease (AD) in patients with Down syndrome (DS) have not been standardised. This study investigated the specific symptoms of AD in the prodromal stage of DS, the mean age at diagnosis at each stage of dementia, and the relationship between intellectual disability (ID) and dementia. PubMed, Web of Science, and Embase were searched for studies on DS, AD, early-stage disease, initial symptoms, and prodromal dementia registered between January 2012 and January 2022. We also performed a meta-analysis of the differences between the mean age at prodromal symptoms and AD diagnosis and the proportion of mild cognitive impairment in patients with mild and moderately abnormal ID. We selected 14 articles reporting the behavioural and psychological symptoms of dementia (BPSD) and memory- and language-related impairments as early symptoms of AD in patients with DS. The specific symptoms of BPSD were classified into five categories: irritability (agitation), apathy, abnormal behaviour, adaptive functioning, and sleep disturbance. The mean age at the diagnosis of prodromal symptoms and AD dementia was 52.7 and 56.2 years, respectively (mean difference, + 3.11 years; 95% CI 1.82-4.40) in the meta-analysis. The diagnosis of mild dementia tended to correlate with ID severity (odds ratio [OR], 1.38; 95% CI 0.87-2.18). The features of behaviour-variant frontotemporal dementia may be clinically confirmed in diagnosing early symptoms of DS-associated AD (DSAD). Moreover, age-appropriate cognitive assessment is important. Further studies are required to evaluate DSAD using a combination of biomarkers and ID-related data.

Adaptive profiles within a broad clinical sample from a transdiagnostic point of view

BACKGROUND

Current literature mainly focuses on adaptive profiles from a categorical perspective but yields inconclusive results. The present study puts a transdiagnostic approach next to a "classical" categorical approach.

METHODS

In this study, 222 children (5-18 years old) with autism and/or intellectual disability participated. Variance analyses, based on standard scores from ABAS-3 at group-level, were conducted in order to compare adaptive domains within categories. A K-Means cluster analysis was used to delineate empirically derived clusters with a similar profile of difference scores at an individual level. Chi-square tests and variance analyses were used to investigate the distribution of variables across clusters.

RESULTS

From a categorical perspective, results were in line with current literature. A transdiagnostic perspective revealed three adaptive profiles (Homogeneous, Social, and Practical). No perfect match was found between specific adaptive profiles and diagnostic categories.

CONCLUSIONS

A transdiagnostic perspective sheds light on the heterogeneity within and the overlap across diagnostic categories.

Social abilities in young Mexicans with Down syndrome during the COVID-19 pandemic

Background: Social abilities include interpersonal skills, interaction, and social responsibility. The nature of these abilities has not been explored in young people with Down syndrome (DS) during the social isolation of the COVID-19 pandemic. Method: The aim of this online study was to describe the social profile of a group of 30 Mexican people with DS, with a chronological age of 15-29 years, and explore the variables related to their psychosocial profiles. A sociodemographic questionnaire, mental age examination, and socialization battery were applied. Social behavior was analyzed in domains that facilitate socialization (leadership, joviality, social sensitivity, respect/self-control), in domains that disrupt socialization (aggressiveness/stubbornness, apathy/withdrawal, anxiety/shyness), and on a global scale. Results: Participants' scores in the facilitative domains were above average, and their scores in the disruptive domains were below average, as expected. Scores on the respect/self-control scale were associated with chronological age (CA), and those on the global scale with mental age (MA). Discussion: No impairments were found in the social skills of young people with DS according to the parameters of the scale. The development of the social profile with CA and MA stimulates cognition and promotes independence, autonomy, and proactivity. Parents' role in regulating children's behavior was an important factor in managing their social isolation during the COVID-19 pandemic.

Caregivers evaluate independence in individuals with Down syndrome

Independence is both a sense of autonomy and self-reliance coupled with the skills to complete tasks without assistance. Questionnaire of caregivers of individuals with Down syndrome asked about factors related to independence on six topics: safety, communication, self-care, daily living, social/leisure, and vocational/employment. Responses from 408 caregivers to an independence questionnaire were received, and summarized using means and frequencies. Top goals by topic were safety from sexual abuse, communicating wants and needs, toileting independently, living independently/semi-independently, engaging in leisure time appropriately, and reading and writing. Independence is a complex, multifactorial phenomenon which varies among individuals with DS.

Overexpression of miR-99a in hippocampus leads to impairment of reversal learning in mice

As one of the most common human genetic disorders, Down syndrome (DS) is characterized by a mild-to-moderate cognitive disability, which mainly results from genes overexpression on chromosome 21. The expression of miR-99a, a gene harboring on chromosome 21, is increased by 50 folds in DS brain samples. This study aims to investigate the effect of miR-99a overexpression in the hippocampus on mouse behaviors and explore the underlying mechanisms. Lentivirus vectors were delivered into the hippocampus for focal miR-99a overexpression in mice. Then behaviors were observed by an open field, elevated plus maze, rotarod motor test, and Morris water maze. The genes affected by miR-99a were identified by RNA sequencing (RNA-seq) and confirmed by quantitative RT-PCR (qRT-PCR) in samples isolated from the hippocampus injected with lentivirus-GFP-miR-99a or lentivirus-GFP vectors. It was found that the expression of miR-99a with intrahippocampal delivery of lentivirus-GFP-miR-99a resulted in reversal learning impairment in mice although it had no influence on motor function and anxiety. Meanwhile, RNA-seq results showed that 92 genes including mRNAs and microRNAs were significantly regulated by miR-99a, consistent with qRT-PCR consequence. Moreover, dual-luciferase reporter assay showed that miR-99a could directly bind to the 3'-untranslated regions (3'UTR) of target genes (Clic6 and Kcnj13) with an inhibitory effect on their activity. Furthermore, we also found that miR-99a overexpression affected different biological processes by bioinformatic analyses. Our study showed that miR-99a overexpression in the hippocampus leads to cognitive impairment through regulating the expressions of various genes, which reveals a novel function of miR-99a and provides new insights into understanding the pathophysiologic process of DS.

Description of Daily Living Skills and Independence: A Cohort from a Multidisciplinary Down Syndrome Clinic

Levels of independence vary in individuals with Down syndrome (DS). We began this study to describe the current life skills in our clinic population of children and adults with DS. We collected and reviewed demographics, living situation, and life skills from an electronic intake form used in clinic procedures. Descriptive statistics for this cohort study included mean, standard deviation, and frequencies. From 2014–2020, 350 pediatric and 196 adult patients (range 0–62 years) with a first visit to the Massachusetts General Hospital Down Syndrome Program are described. Pediatric patients were most often enrolled in school, and in an inclusion setting. Adult patients were most often participating in a day program, living with family, and wanted to continue living with family in the future. Most (87%) of adults with DS communicated verbally, though fewer could use written communication (17%). Life skills of greatest importance to adolescents and adults with DS included: learning about healthy foods (35%), preparing meals (34%), providing personal information when needed (35%), and describing symptoms to a doctor (35%). Life skills for patients with DS are varied; those associated with a medical appointment, such as sharing symptoms with the doctor, could improve for greater independence.

Opportunities, barriers, and recommendations in down syndrome research

BACKGROUND

Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community.

OBJECTIVE

The National Down Syndrome Society (NDSS) and the LuMind IDSC Foundation worked together with scientific and medical experts to develop recommendations for the NIH research plan.

METHODS

NDSS and LuMind IDSC assembled over 50 experts across multiple disciplines and organized them in eleven working groups focused on specific issues for people with DS.

RESULTS

This review article summarizes the research gaps and recommendations that have the potential to improve the health and quality of life for people with DS within the next decade.

CONCLUSIONS

This review highlights many of the scientific gaps that exist in DS research. Based on these gaps, a multidisciplinary group of DS experts has made recommendations to advance DS research. This paper may also aid policymakers and the DS community to build a comprehensive national DS research strategy.

Screening of Cognitive Changes in Adults with Intellectual Disabilities: A Systematic Review

Background and Aims: Screening and assessment of cognitive changes in adults with Intellectual Disabilities (ID), mainly Down Syndrome (DS), is crucial to offer appropriate services to their needs. We present a systematic review of the existing instruments assessing dementia, aiming to support researchers and clinicians’ best practice. Methods: Searches were carried out in the databases Web of Science; PubMed; PsycINFO in March 2019 and updated in October 2020. Studies were selected and examined if they: (1) focused on assessing age-related cognitive changes in persons with ID; (2) included adults and/or older adults; (3) included scales and batteries for cognitive assessment. Results: Forty-eight cross-sectional studies and twenty-seven longitudinal studies were selected representing a total sample of 6451 participants (4650 DS and 1801 with other ID). In those studies, we found 39 scales, questionnaires, and inventories, and 13 batteries for assessing cognitive and behavioural changes in adults with DS and other ID. Conclusion: The most used instrument completed by an informant or carer was the Dementia Questionnaire for Learning Disabilities (DLD), and its previous versions. We discuss the strengths and limitations of the instruments and outline recommendations for future use.

The functional impact of cognition in adults with autism spectrum disorders

Purpose and aim: The overall aim of this study was to examine the relationship between adaptive function and cognitive factors in young adults diagnosed with autism spectrum disorder (ASD) in adult age.Methods: The study included 30 adults (age 18-30) diagnosed with ASD in adulthood. All participants were clinically referred to an adult psychiatric clinic for assessment. Adaptive functioning was measured with Adaptive Behavior Assessment System - 2nd edition (parent version). Wechsler scales of intelligence and Delis-Kaplan Executive Function System were used to measure intelligence and executive function.Results: We found considerable adaptive functioning deficits regardless of Full Scale Intelligence Quotient (FSIQ) level. FSIQ, working memory and processing speed were positively associated with adaptive functioning. No associations were found between adaptive functioning and cognitive flexibility, inhibition, word generation or shifting. Regression analysis showed that working memory and processing speed predicted 23% of the variance in adaptive functioning in this group.Conclusions: The results suggest that cognitive dysfunction could be an important area for intervention to improve adaptive functioning in ASD.

Plasma neurofilament light chain: A potential prognostic biomarker of dementia in adult Down syndrome patients

People with Down syndrome (DS) are at high risk of developing Alzheimer disease (AD) with aging. The diagnosis and treatment trials are hampered by a lack of reliable blood biomarkers. Plasma neurofilament light chain (NfL) is one of the established biomarkers of AD, suggesting that it may be useful as an indicator of dementia in DS patients. The aims of this study were: 1) to examine whether plasma levels of NfL in DS patients are correlated with decreased adaptive behavior scores one year after sample collection, and 2) to compare plasma levels of NfL in adults with DS and an age-matched healthy control population. In this study, plasma levels of NfL in 24 patients with DS and 24 control participants were measured by the single-molecule immunoarray (Simoa) method. We observed significantly increased plasma NfL levels in the DS compared with the control group. There was a significant correlation between age and levels of plasma NfL in both groups. This age-dependent elevation was steeper in the DS compared with the control group. Moreover, elevated plasma NfL was associated with decreased adaptive behavior scores one year later, after age-adjustment. Previously reported blood-based biomarkers available in Simoa for DS, plasma total tau and phosphorylated tau, were not significantly correlated with the annual decrement of adaptive behavior scores after age-adjustment. These results suggest that plasma NfL has the potential to serve as an objective biomarker to predict dementia in adult DS patients.

Down Syndrome and Alzheimer's Disease: Issues and Implications for Social Work Practice

Owing to recent medical advancements, people with Down Syndrome (DS) are now able to live considerably longer lives and thus experience a variety of complex issues as they age. Alzheimer's Disease (AD) frequently occurs in older adults who have DS, but few practice guidelines exist to inform social work practice with older adults who have this dual diagnosis. This commentary will highlight the connection between these two conditions within a neurobiological framework and discuss implications for practice based on the available literature on this intersection of ability status, cognitive status, and age.

Adaptive behaviour, executive function and employment in adults with Down syndrome

BACKGROUND

Individuals with Down syndrome (DS) demonstrate difficulties with aspects of executive function (EF) and adaptive behaviour across the lifespan. There is a current lack of information regarding how these difficulties relate to employment outcomes in adulthood. This study evaluated the adaptive behaviour and EF profiles of individuals with DS during early adulthood and the association between these areas of functioning and employment status.

METHODS

Parents or caregivers of primarily young adults with DS (n = 31; mean chronological age = 25.9 years; SD = 5.92) completed the Vineland Adaptive Behavior Scales - Second Edition the Behavior Rating Inventory of Executive Function - Adult version and a demographic questionnaire that requested information regarding adult employment status.

RESULTS

Findings indicated a distinct pattern of relative strengths and challenges in adaptive behaviour and EF. In addition, the EF sub-domain of working memory was a significant predictor of employment status.

CONCLUSIONS

Specific aspects of the DS cognitive profile may have an important influence on employment status in primarily young adults with DS. Implications for interventions are discussed.

Outcome Measures for Clinical Trials in Down Syndrome

Increasingly individuals with intellectual and developmental disabilities, including Down syndrome, are being targeted for clinical trials. However, a challenge exists in effectively evaluating the outcomes of these new pharmacological interventions. Few empirically evaluated, psychometrically sound outcome measures appropriate for use in clinical trials with individuals with Down syndrome have been identified. To address this challenge, the National Institutes of Health (NIH) assembled leading clinicians and scientists to review existing measures and identify those that currently are appropriate for trials; those that may be appropriate after expansion of age range addition of easier items, and/or downward extension of psychometric norms; and areas where new measures need to be developed. This article focuses on measures in the areas of cognition and behavior.