Rett syndrome (RTT) is a postnatal neurological disorder caused by loss-of-function mutations in the gene that encodes methyl-CpG binding protein 2. RTT is characterized by initially normal development, followed by developmental regression at 6 to 18 months of age. Individuals with RTT subsequently develop motor deficits, impaired learning and memory, and breathing abnormalities. In this review, we summarize recent findings on how neuronal circuitry is impaired in RTT and how deep brain stimulation and presymptomatic, task-specific training significantly improve learning and memory in RTT mice. Translating these findings to clinical applications, interventional studies have shown initial evidence that structured behavioral exercises can benefit individuals with RTT. Based on the converging evidence from preclinical and clinical research, we advocate for early-stage intensive behavioral training to supplement other therapeutic approaches and enhance treatment outcomes.
The Washington Group Short Set on Functioning (WG-SS) allows for the identification of functional limitations across severity levels. Incorporating the WG-SS into Special Olympics (SO) surveys serves to understand functional support needs and inform SO programming for people with intellectual disability. This study examined functioning using both a restrictive and a broad definition of limitation among 525 U.S. SO athletes who completed an online survey in 2022. Self- and proxy-reported outcomes were compared to National Health Interview Survey (NHIS) estimates. Nearly a quarter of SO athletes (24.2%) reported any functional limitation under the restricted definition, while over three quarters (82.1%) reported limitations under the broad definition. Differences emerged between self- and proxy-reported data. Compared with NHIS age-adjusted estimates, SO athletes had higher prevalence ratios across all six domains, including self-care (PR = 12.93) and communication (PR = 11.21). These findings underscore functional diversity among SO athletes and inform programming and disability surveillance.
This study examined demographics, social determinants of health, comorbidities, and outcomes (mortality and readmissions) of hospitalized patients with intellectual and developmental disabilities (IDD). The sample included 39,256 hospital admissions for adult inpatients with IDD from four states. Logistic regression analyzed factors influencing 30-day readmission and in-hospital mortality. Results showed a 17.5% 30-day readmission rate. Black race, Medicare/Medicaid insurance, and admission from another facility were associated with higher odds of readmission. Age, Medicare insurance, and admission from emergency rooms, another hospital, or facility were associated with higher odds of in-hospital mortality. The study highlights the complex interplay of factors affecting outcomes for patients with IDD, emphasizing the need for targeted interventions and improved hospital care to address health disparities in this population.
Although early mathematical competencies are crucial for students with intellectual disability (ID), little is known about their cognitive predictors in this population. This study investigates the relationship between early mathematical competencies and intelligence, working memory (WM), as well as years of schooling. In a cross-sectional design, 76 primary school students were assessed using tests for quantity-number competencies, intelligence, and WM. Correlations and quantile regression analyses were conducted. Fluid intelligence showed a stable positive effect across all achievement levels, whereas visual-spatial WM had a particularly strong effect in lower-performing students. The results suggest that cognitive factors, particularly fluid intelligence and visual-spatial WM, play a central role in the development of mathematical competencies in students with ID.
Adaptive behavior is an essential criterion in defining intellectual disability. All three major diagnostic systems (American Association on Intellectual and Developmental Disabilities [AAIDD], Diagnostic and Statistical Manual of Mental Disorders [5th ed. text revision], and International Classification of Diseases [11th ed.]) conceptualize adaptive behavior as consisting of three domains: conceptual, social, and practical skills. Few of the existing standardized adaptive behavior measures were constructed using this tripartite conceptual model of adaptive behavior. The Diagnostic Adaptive Behavior Scale (DABS) was developed and validated using this tripartite model of adaptive behavior. This article summarizes the results of a confirmatory factor analysis that confirmed the tripartite model of the DABS and provided support that the DABS is a reliable measure to assess conceptual, social, and practical adaptive skills. The estimated internal consistency for the conceptual, social, and practical skill domains assessed on the DABS ranged from .97 to .99, indicating excellent levels of reliability.
Fragile X syndrome (FXS) is a rare condition that can require lifelong specialized care for optimal management. We describe census-based characteristics of general U.S. populations defined by proximity to FXS specialty clinics to better understand potential barriers to access. We used Geographic Information System software to estimate drive times from U.S. census tract centroids to FXS clinics. Of the contiguous U.S. population, 36.4% lives ≤1 hour from the closest FXS clinic in the same state; 32.4% live >1 to 4 hours, 7.3% live >4 hours, and 23.8% have no FXS clinic in their state. Individuals residing >1 hr from or in a state without an FXS clinic, compared to <1 hr, were more commonly non-Hispanic White, had household income below 150% poverty level, had one or more disabilities, and lived in a household without an internet subscription. Populations living ≤1 hr from an FXS clinic more commonly spoke limited English, lived in multiunit housing, and did not have a vehicle. These results can be used to identify areas of higher need for improving access to specialty care, inform efforts to reduce disparities related to access, and facilitate more optimal healthcare for people with FXS.
Increased life expectancy among people with intellectual disability has led to a growing prevalence of dementia, highlighting the need to understand how quality of life is experienced during its early stages. This qualitative study explored perceived quality of life among adults with mild to moderate intellectual disability and mild dementia residing in long-term care facilities in Chile. Semi-structured interviews were conducted with 86 individuals, using accessible communication strategies and visual supports. Data were analyzed using reflexive thematic analysis, informed by Schalock and Verdugo's quality of life framework. Five interrelated themes described how quality of life was experienced through the organization of activities and environments, emotional and physical experiences, relationships and participation, involvement in decision-making and support, and perceived changes over time. Quality of life in early-stage dementia was articulated through concrete experiences of participation, relationships, and support, underscoring the importance of everyday contexts as key sites where well-being is experienced and sustained.
The NIH Toolbox Cognition Battery (NIHTB-CB) assesses crystallized verbal skills,and shows strong psychometric properties and sensitivity to developmental change in intellectual and developmental disabilities. However, whether gains in NIHTB-CB Crystallized Cognition reflect improvements in broader verbal abilities is unclear, and this has implications for clinical interpretation of the measure in the context of treatment studies. Two-hundred sixty-three participants completed NIHTB-CB Crystalized Cognition subtests (Picture Vocabulary, Oral Reading Recognition) and Stanford-Binet 5th ed. subtests (Verbal Knowledge, Verbal Fluid Reasoning) at baseline and at two-year follow-up. Bivariate latent change score models examined whether changes in Crystalized Cognition were related to changes in broader verbal skills. Changes in Crystalized Cognition were significantly related to changes in Verbal Knowledge (β = 7.92, p = .009) and Verbal Fluid Reasoning (β = 4.91, p = .018). Higher baseline Crystalized Cognition predicted greater improvement in these verbal domains, while higher initial verbal scores also predicted more Crystalized Cognition growth. Change in the NIHTB-CB Crystalized Composite was significantly related to growth in verbal reasoning in children and young adults with IDD. This may indicate that the Crystalized Composite is a useful proxy for broader verbal skills, underscoring its clinical relevance.
Few studies examine the impacts of structural inequities on service access and use for people with intellectual and developmental disabilities (IDD). This secondary data analysis used data from the Medical Expenditure Panel Survey and the American Community Survey to examine the association of race, neighborhood segregation, and hospital and outpatient use among people with IDD. Our sample included children and adults with a diagnosis of IDD. Multilevel logistic regression models with random intercepts were used to assess the association between race, neighborhood segregation, and emergency room (ER), hospital, and any outpatient use. Our analyses adjusted for individual-level predisposing, enabling, and need characteristics. Ninety-four percent of the sample reported use of outpatient services, 15% had at least one ER visit, and 5% had at least one hospitalization. Living in a segregated neighborhood was associated with lower odds of any outpatient use (OR = 0.35, 95% CI: 0.15-0.85). We found no evidence of association between neighborhood segregation and hospital or ER use. Other (vs. White) race was associated with lower odds of any outpatient use (OR = 0.33, CI: 0.12-0.90) and higher odds of hospital use (OR = 8.00, CI: 2.26-28.35). Scholars need larger integrated datasets and more nuanced methods for longitudinal analyses to map associations better between race, neighborhood segregation, and their impact on service use.
Latino children with intellectual and developmental disabilities (IDD) face disparities in accessing specialty services. Using 2020-2023 National Survey of Children's Health data (N = 2,497), we conducted logistic regressions to examine how parental nativity and household language affect specialty services use among Latino children with IDD. While children of immigrant parents had lower odds of service use, this association was explained by household language. Children in Spanish-speaking households were significantly less likely to receive services (OR = 0.53, CI = 0.33-0.84). The mediation analysis further highlights that language, more than nativity, drives disparities. Therefore, efforts to improve access should include Spanish-speaking providers and culturally responsive care.
The Affect in Play Scale (APS) is a standardized pretend play assessment that measures cognitive and affective skills in school-aged children. We examined the comparative utility of the APS via telehealth across three diagnostic groups. Ninety-four children ages 6 to 9 who were either typically developing or had high-functioning autism spectrum disorder or Prader-Willi syndrome completed the APS either in-person or via videoconferencing in a single mode administration design. Equivalence analyses compared in-person versus remote APS scores within diagnostic groups. Paired samples t tests revealed no significant differences between groups on all APS variables (ps > .073). Results support equivalence and feasibility of the remote APS for school-aged children with and without developmental differences. Recommendations for administration are discussed.
Mazurek et al. (2019) put forth an Expressive Language (EL) score based on the Autism Diagnostic Observation Schedule, Second Edition Module administered and Item A1, establishing convergent validity with expressive language assessments for autism. The current study examines EL score relationships with transcribed language samples-including sensitivity to change-across 6- to 23-year-old individuals in three diagnostic groups: autism, Down syndrome, and Fragile X syndrome. Results demonstrate convergent validity of EL score with language complexity and lexical diversity, and variable patterns of divergence with talkativeness and nonverbal participation. In contrast to mean length of utterance in morphemes, EL score was not sensitive to 1-year change. These findings support the usefulness of EL score for quickly describing expressive language, but caution against its use as a clinical outcome or measure of change.
There is little knowledge of how to identify depression in the 30% of adults with autism who are non- or minimally speaking (NMS). The current study aims to address this by using parent-reported behaviors to curate a list of indicators of depression in this population. When asked to describe why they think the person is depressed, qualitative analyses found parents (N = 152) frequently identified anhedonia and low mood. Endorsement patterns on existing depression surveys identify traditional depression symptoms like sleep, crying, and activity participation. On the other hand, many items (e.g., repetitive behaviors) were endorsed across groups with and without suspected depression, possibly capturing features of autism. Results inform our understanding of the manifestation of depression in NMS adults with autism and the development of screening tools.
The Supports Intensity Scale-Adult Version (SIS-A) measures the intensity of support needs of people aged 16 and over with intellectual and developmental disabilities. Since its 2004 release, this tool has informed supports planning across the United States and internationally. In 2023, the second edition of the SIS-A was published, featuring updated norms for the scale. This study examines the alignment of score distributions before and after renorming the SIS-A. Findings reveal a strong correlation between scores derived from the original and updated norms, suggesting continuity in score distributions. However, the use of the updated norms resulted in a more normal distribution of scores. Implications for research, policy, and practice are discussed.
DABS-B is the Brazilian adaptation of the Diagnostic Adaptive Behavior Scale, an instrument developed to assess adaptive behavior and assist in the diagnosis of intellectual disability. Culturally adapted and validated, it fills a crucial need in the Brazilian context, where such tools are scarce. This article presents two studies demonstrating its reliability and validity. Study One, involving 30 parent/guardian interviews scored independently by two evaluators, showed strong interrater reliability (ICC = .60 - .97), albeit with slightly lower agreement in the social domain. Study Two, comparing DABS-B with a similar measure in 47 cases, revealed robust correlations (.63-.83), affirming its validity. These findings underscore the promise of DABS-B in Brazil, addressing the current deficit of culturally adapted tools.
Parents of children with disabilities face a high risk of parental burnout due to caregiving demands. This study examined whether mentalization and self-compassion protect against burnout. Conducted in Iran during the 2020-2021 academic year, it involved 911 parents (Mage = 40.02 ± 7.14). Participants completed the Parental Burnout Inventory, Reflective Functioning Questionnaire, and Self-Compassion Scale. Data were analyzed using frequency assessment, X2 tests, one-way analysis of variance, and Generalized Additive Models with SPSS-22 and R 4.0.3. Results showed 1.6% experienced severe burnout, and 26.8% moderate burnout. Higher reflective functioning-both lower tendencies toward hypermentalizing and hypomentalizing-was linked to lower burnout levels. The relationship between self-compassion and burnout was curvilinear: moderate levels of self-compassion were linked to the lowest burnout, while both very low and very high levels were associated with higher burnout risk. Maintaining a balanced capacity for reflective functioning and self-compassion may help reduce parental burnout. These findings suggest that targeted interventions, such as mentalization-based therapy and self-compassion training, could strengthen resilience among caregivers.
Parenting stress is a multifaceted experience, particularly for parents of children with autism and children with other developmental disabilities (DD). While much research focuses on child-specific factors, broader contextual influences are often underexplored. Guided by Belsky's model of parenting stress and ecological systems theory, this study examines how child, parent, and familial factors contribute to parenting stress. Data from 206 families with children aged 3 to 5 years (95 with autism, 111 with DD) were analyzed. Results indicate that child characteristics, such as symptom severity and adaptive behavior, significantly impact parenting stress. Parent (e.g., education level, marital status) and familial variables (e.g., income, number of siblings) also play key roles. Notably, predictors of stress differ across distinct dimensions, suggesting that distinct mechanisms may underlie general distress, daily hassles, and the perceived impact of the child on the family. These findings emphasize the need for targeted, multidimensional intervention strategies.
Wearable biosensors can provide insight into the internal states of individuals with autism with communication challenges; however, sensory sensitivities may make wearable biosensors uncomfortable. We describe our approach for introducing a wrist-worn biosensor (Empatica E4) to participants and using supportive techniques. Most participants (76.6%) were able to wear the biosensor for a duration of 15 minutes. The option to wear a colorful sweatband over the biosensor, verbal encouragement, and edible rewards were found to be helpful. Data collection was unsuccessful for the 23.4% of participants who did not accept wearing the device, which was more common for minimally speaking participants. Tailored approaches and attention to nonverbal signs of assent or discomfort are essential for conducting wearable biosensor research with individuals with autism.
This study investigated the effects of sensory-based treatments (SBT) combined with active transcranial direct current stimulation (tDCS) of the left prefrontal cortex (SBT+AtDCS), and SBT combined with sham tDCS (SBT+StDCS) in autism spectrum condition (ASC). Eleven ASC children were randomly assigned to receive either SBT+AtDCS or SBT+StDCS for 10 sessions over 2 weeks. All children exhibited significant improvement in their ability to regulate and respond to sensory stimuli after treatment. The SBT+AtDCS group showed significant reductions in autism severity and behavioral difficulties compared to the SBT+StDCS group. This preliminary report is the first to suggest that SBT combined with active tDCS may alleviate symptoms associated with ASC. Future research with a larger sample, neural measures, and a longitudinal design is required for validation.
This study explored the sustainability of the acute effects of aerobic (AE) and resistance (RE) exercises on reaction time (RT) in individuals with intellectual disability. Twelve adolescents with intellectual disability performed visual simple RT (SRT), choice RT, and auditory SRT tests before and after three intervention sessions: AE, RE, and a control session. RTs were assessed before (Pre-EX), immediately (Post-0), 15 minutes and 30 minutes after exercise. Compared to Pre-EX, all RT declined in all time points after both RE and AE (p < .001; large effect). These decreases were (p < .05; large effect) higher for the RE compared to the AE at Post-0. AR and RE are recommended before engaging in cognitively demanding tasks, ideally within 30 minutes.
