Focusing on autism symptoms masks sex-specific needs of autistic children: An example from the Sydney Child Neurodevelopment Research Registry.

Lay abstract: Studies have shown that there is a difference between biological sex at birth in autism spectrum disorder. There remains a lack of understanding about how the symptoms of autism differ between assigned males at birth and assigned females at birth. We looked at the presence of sex differences in a large group of autistic toddlers, children and adolescents, who were seen in a large diagnosis and assessment clinic. They participated in measures of intelligence/development, social/communication skills and behaviour. Their adaptive skills were evaluated and other clinical and information were collected. Assigned males at birth displayed more autism characteristics and greater symptom autism severity than assigned females at birth. There were no statistically significant differences between assigned males at birth and assigned females at birth on any measure of intellectual assessment. Assigned females at birth showed better nonverbal performance than assigned males at birth on formal developmental assessments. Children assigned males at birth received assessments 6 months earlier than children assigned females at birth. Externalising behaviour problems were more evident in assigned males at birth. This study provides evidence to show that autistic children assigned females at birth and assigned males at birth differ in terms of autism symptoms and severity and age at diagnosis based on a sample recruited in a real-world clinic. It highlights the importance of the growing debate between balancing assessments of symptoms with assessment of adaptive function.