Abstract
Background: Sex differences in the prevalence of neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are well documented, but studies examining sex differences in social and communication function remain limited and inconclusive. Objectives: The objective of this study is to conduct a meta-analysis of sex differences in social-communication function in children with ASD or ADHD and typically developing controls. Methods: Using PRISMA, a search was performed on Medline and PSYCHINFO on English-language journals (2000-2017) examining sex differences in social and communication function in ASD and ADHD compared to controls. Inclusion criteria: 1) peer reviewed journal articles, 2) diagnosis of ASD or ADHD and controls, 3) age 6-18 years, 4) measures of social-communication function, and 5) means, standard deviations, and sample sizes reported in order to calculate standardized mean differences (SMD). Results: Eleven original/empirical studies met inclusion criteria for ASD and six for ADHD. No significant sex differences were found between ASD and controls in social (SMD = -0.43; p = 0.5; CI: -1.58-0.72), or communication function (SMD = 0.86; p = 0.5 CI; -1.57--3.30) and between ADHD and controls in social function (SMD = -0.68: p = 0.7, CI: -4.17-2.81). No studies evaluated sex differences in communication in ADHD. Significant heterogeneity was noted in all analyses. Type of measure may have partially accounted for some variability between studies. Conclusions: The meta-analysis did not detect sex differences in social and communication function in children with ASD and ADHD; however, significant heterogeneity was noted. Future larger studies, controlling for measure and with adequate numbers of female participants are required to further understand sex differences in these domains.