This study examined individual differences in ADHD symptoms and executive function (EF) in children with Down syndrome (DS) in relation to the dopamine receptor D4 (DRD4) gene, a gene often linked to ADHD in people without DS. Participants included 68 individuals with DS (7-21 years), assessed through laboratory tasks, caregiver reports, and…

The aim of this cross-sectional study was to analyze the typical aging process in adults with Down syndrome, focusing on its variability. The sample comprised 120 adults with Down syndrome who were free of dementia. Ages ranged from 20 to 69 years. Each participant was assessed on cognitive functioning and social adaptation, and was checked for…

Individuals with intellectual disability (ID) or Down syndrome (DS) may be at greater risk of osteoporosis. The purpose of this study was to compare bone mineral density (BMD) of DS, ID, and non-intellectually disabled (NID) populations. In each group, 33 participants between the ages of 28 and 60 years were compared. BMD was measured with…

Rule-based category learning was examined in youths with Down syndrome (DS), youths with intellectual disability (ID), and typically developing (TD) youths. Two tasks measured category learning: the Modified Card Sort task (MCST) and the Concept Formation test of the Woodcock-Johnson-III (Woodcock, McGrew, & Mather, 2001). In regression-based…

We investigated executive functioning (EF) in children with Down syndrome (DS; n = 25) and typically developing (TD) children matched for mental age (MA; n = 23) using the Behavior Rating Inventory of Executive Function-Preschool. We sought to (1) compare children with DS to a developmentally matched control group, and (2) to characterize the EF…

Children with intellectual disability were randomly assigned to receive Milieu Communication Teaching (MCT) at one 1-hr session per week (low dose frequency, LDF) or five 1-hr sessions per week (high dose frequency, HDF) over 9 months (Fey, Yoder, Warren, & Bredin-Oja, 2013. Non-Down syndrome (NDS) and Down syndrome (DS) subgroups were matched…

The role of early childhood mastery motivation as a predictor of executive function 20 years later was examined in a sample of 39 individuals who had early diagnosed developmental disabilities. Multilevel modeling was used to analyze predictors of accuracy and response time on a Flanker task measuring executive function. As predicted, participants…

The present study addresses critical gaps in the literature by examining residential transitions among 303 adults with intellectual disability (ID) over 10 years (Part 1) and 75 adults with Down syndrome over 20 years (Part 2). All adults lived at home at the start of the study, but many moved to a variety of settings. Several characteristics of…

Parental characteristics were significant predictors of health, functional abilities, and behavior problems in adults with Down syndrome ("n" ?=? 75) over a 22-year time span, controlling for initial levels and earlier changes in these outcomes. Lower levels of behavior problems were predicted by improvements in maternal depressive…

Augmentative and alternative communication (AAC) systems often supplement oral communication for individuals with intellectual and communication disabilities. Research with preschoolers without disabilities has demonstrated that two visual--perceptual factors influence speed and/or accuracy of finding a target: the internal color and spatial…

This study evaluated the impact of a computerized visuospatial memory training intervention on the memory and behavioral skills of children with Down syndrome. Teaching assistants were trained to support the delivery of a computerized intervention program to individual children over a 10-16 week period in school. Twenty-one children aged 7-12…

The influences of verbal mental age (VMA) and performance mental age (PMA) on cognitive flexibility were examined among a group of participants with Down syndrome (DS), in order to disentangle the relative contributions of each. The impaired cognitive flexibility typically observed among individuals with DS in combination with uneven VMA and PMA…

We evaluated a 12-week recreation center-based healthy lifestyle intervention for 30 obese home-dwelling young adults (YA) with intellectual disabilities. Three cohorts participated: YA only, YA and parents, and parents only. The YA cohorts received a nutrition/exercise intervention; parents focused on modeling healthy lifestyle behaviors.…

This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs used in behavioral research on cognition and…

Whereas pragmatic language difficulties are characteristic of both autism and Fragile X syndrome, it is unclear whether such deficits are qualitatively similar or whether certain skills are differentially affected. This study compared narrative competence in boys with autism, Fragile X syndrome, Down syndrome, and typical development. Results…