A meta-analytic review of adaptive functioning in fetal alcohol spectrum disorders, and the effect of IQ, executive functioning, and age

Abstract

Introduction: Fetal alcohol spectrum disorders (FASD) are highly prevalent developmental disabilities associated with prenatal alcohol exposure. In addition to varied strengths and unique talents, people with FASD experience significant challenges, including in adaptive functioning. Adaptive functioning refers to skills related to everyday life such as communication, practical skills, and social skills. For the current review, we aimed to understand how adaptive functioning in FASD compares to that of alcohol nonexposed individuals and those with attention deficit-hyperactivity disorder (ADHD). Additionally, we investigated how this relationship may change based on IQ, executive functioning, and age.

Method: The current review was registered in the International Prospective Register of Systematic Reviews. Studies were eligible for inclusion if they measured adaptive functioning and included an FASD group and at least one eligible comparison group. Articles available in May 2021 in PubMed, PsycInfo, Scopus, and ProQuest Dissertations were searched. Publication bias was assessed using Egger's regression and three-level random effects models were computed for all domains of adaptive functioning. Possible moderation by IQ, executive functioning, and age were investigated when heterogeneity analyses were significant. A post hoc moderation analysis of recruitment method was also completed.

Results: Thirty studies were included. Individuals with FASD had significantly lower adaptive functioning than other groups, with effect sizes ranging from 1.04 to 1.35 compared to alcohol nonexposed groups and from 0.30 to 0.43 compared to ADHD groups. No significant moderating effects were found for IQ or age; executive functioning significantly moderated communication skills in FASD compared to the alcohol nonexposed group. Recruitment method significantly affected this relationship, with larger effect sizes on average found for clinically identified samples than at-risk or population samples.

Conclusions: Individuals with FASD have impairments in adaptive functioning relative to alcohol nonexposed and ADHD groups, regardless of IQ, executive functioning, or age. Limitations of the review include small sample sizes in some comparisons and a limited age range.

Keywords: FASD; adaptive functioning; fetal alcohol spectrum disorder; meta-analysis; prenatal alcohol exposure.