Adaptive behavior in adolescents and adults with Down syndrome: Results from a 6‐month longitudinal study

Abstract

Measures of adaptive behavior are important in the assessment and treatment of individuals with intellectual disabilities (ID). The purpose of the current study was to evaluate the stability of an established and a novel measure of adaptive behavior over time, and their suitability as outcome measures in clinical trials targeting individuals with Down syndrome (DS). This 6-month, longitudinal, noninterventional, multinational study included adolescents (12-17 years) and adults (18-30 years) with DS. Participants were from seven countries (11 different sites) with English, Spanish and French as their native language. The Vineland Adaptive Behavior Scales-II (VABS-II) and a newly developed Clinician Global Impression (CGI) scale were administered at baseline, 1 and 6 months. Adults had lower composite standard scores on all domains of the VABS-II compared with adolescents. The communication domain was a weakness relative to the socialization and daily living skills domains on the VABS-II and the CGI-Severity scale. These findings were stable over 6 months, as exhibited by high intraclass correlations (>0.75). These results provide valuable baseline data for use in trial design and endpoint selection for studies including individuals with DS. ClinicalTrials.gov identifier: NCT01580384. K E Y W O R D S adaptive behavior, CGI-I, CGI-S, Down syndrome, intellectual disability, VABS-II

Executive functions and adaptive behaviour in individuals with Down syndrome

“…They were both relatively strong on Socialisation and weak on Communication and Daily Living Skills, but preschoolers scored higher for Daily Living Skills than school-age children. These results are in line with previous reports of a relative strength in Socialisation and weakness in Communication (Dykens et al 2006;Fidler et al 2006;Van Duijn et al 2010;Will et al 2018;Spiridigliozzi et al 2019) in children with DS. More variability has been reported regarding Daily Living Skills, and it may be that environmental variables (such as living conditions or education) have a role in modulating the development of these skills.…”

“…going up and down the stairs or using scissors). When this tool has been used to assess children and adolescents with DS between 1 and 17 years old, it has identified a profile characterised by strengths in Socialisation and weaknesses in Communication and Motor Skills (Dykens et al 2006;Will et al 2018;Spiridigliozzi et al 2019). A global impairment in adaptive behaviour emerges for infants and toddlers with DS (5-45 months old) by comparison with typically developing children.…”

“…A global impairment in adaptive behaviour emerges for infants and toddlers with DS (5-45 months old) by comparison with typically developing children. The former have difficulties across all domains already in the first year of life (Will et al 2018), with their standard scores declining as they grow older (Will et al 2018;Spiridigliozzi et al 2019). Young children with DS also show a deceleration in adaptive trends as they grow up, the most pronounced discrepancies between DS and typical development involving motor and communication skills (Will et al 2018).…”

Is the Age of Developmental Milestones a Predictor for Future Development in Down Syndrome?

“…Similar to cognitive development, difficulties in adaptive skills are visible from early in life and the development of children with DS follows the same trajectory of TD individuals, but at a slower pace [ 16 ]. Previous research shows a peak and valleys profile with weaknesses in communication and motor skills, while socialization emerges as a strength [ 17 , 18 ]. Evidence of these developmental profiles can be found early in development [ 19 ].…”

A randomized, double-blind, placebo-controlled phase II trial to explore the effects of a GABAA-α5 NAM (basmisanil) on intellectual disability associated with Down syndrome

“…The primary endpoint was designed to capture potential improvements in intellectual functioning from multiple perspectives by combining direct measures of cognition (RBANS memory tasks), clinician ratings (DS-CGI-I), and caregiver-reported measure (VABS-II). These measures were selected based on their suitability for the population, reliability, stability over time, and feasibility of implementation, as previously determined in a 6-month observational study with a comparable study design and population [22,23]. In the current study, the stability over time of most measures was not replicated; improvements were observed across placebo and treatment arms over 6 months on multiple variables including the VABS-II composite scores, DS-CGI-I, BRIEF-P, and PedsQL.…”