Sex differences in core autism symptoms have not been fully investigated. Boys with autism have been reported to show less pretend play, more inappropriate stereotypic play, and more unusual visual interests than girls with autism. Cognitive ability is hypothesized to influence core autism symptoms.
To study sex differences in core autism symptoms according to DSM-IV diagnostic criteria.
All children born in
Males met on average 0.63 (95%CI=0.20-1.06; p=0.004) more items from DSM-IV diagnostic criteria than females. Further, males on average met 0.29 (95%CI=0.07-0.51; p=0.011) more items concerning impaired communication and 0.28 (95%CI=0.07-0.50; p=0.011) more items concerning restricted behaviours than females. A similar trend was seen concerning impaired social interaction.
For autism cases without mental retardation males overall met on average 0.69 (95%CI=-0.06-1.44; p= 0.073) more items than females and on average 0.66 (95%CI=0.29-1.02; p=0.001) more items concerning restricted behaviours when adjusting for age. Similar trends were seen concerning impaired communication and impaired social interaction. For cases with mental retardation largely the same trend was found.
In a population-based cohort of validated cases of autistic disorder compliance with DSM-IV diagnostic criteria items differed significantly between sexes: Consistently males met more items than females. Current diagnostic criteria may favour diagnosis of males. More studies are needed on female autistic behaviour.