Affiliation: | 1. Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan;2. Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan United Graduate School of Child Development, Hamamatsu University School of Medicine, Hamamatsu, Japan;3. Center for Consultation and Support for Developmental Disorders, Hamamatsu, Japan;4. Institute of Child Developmental Science Research, Hamamatsu, Japan;5. Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan Queens College and Graduate Center, City University of New York, New York City, New York, USA |
Abstract: | Aim Little is known about early manifestations of autism spectrum disorders (ASD) in females, including those who may be overlooked by the current diagnostic criteria. We longitudinally explored sex differences in the trajectories of cognitive and motor functions and adaptive behaviors in children with different levels of autistic traits. Methods The participants were 824 children from the Hamamatsu Birth Cohort for Mothers and Children (HBC Study), Japan, who were classified into three autistic trait groups—low, moderate, and high—based on the Social Responsiveness Scale–Second Edition. Cognitive and motor functions were measured at seven time-points from 0.5 to 3.5 years of age using the Mullen Scales of Early Learning. Adaptive behaviors were measured at five time-points from 2.7 to 9 years of age using the Vineland Adaptive Behavior Scales–Second Edition. Trajectories were depicted using latent growth curve modeling. Results Sex-specific trajectories were observed in the high-autistic-trait group, with only males showing a temporary decline in expressive language around the age of 2 years and a slight improvement thereafter. They also showed a slight improvement around 3 years in the adaptive behavior communication domain but a gradual downward trend later. Females in the high-autistic-trait group showed no distinct manifestation before the age of 3 years but showed a downward trend after 3.5 years in the adaptive behavior communication domain. Conclusion Females and males with higher autistic traits than their same-sex peers, independent of clinical diagnosis, may have different phenotypes in certain neurodevelopmental domains during infancy and early childhood. |