The incidence of autism is similar in boys and girls, although boys are diagnosed earlier

"The findings of a study conducted on a sample of 2.7 million people in Sweden over a 35 year period, and published this Thursday in the medical journal BMJ, suggest that the male to female ratio of Autism Spectrum Disorder (ASD) has decreased over time. In early childhood, before the age of 10, the male to female ratio is 3:1 (the most widely accepted ratio a few years ago was 4:1)."

"The analysis included a sample of more than 2.7 million people born in Sweden between 1985 and 2020, followed from birth to a maximum age of 37. More than 78,000 received a ASD diagnosis. The detection of this disorder increased with age throughout childhood, peaking for boys between the ages of 10 and 14 and for girls between 15 and 19. The authors do not address the question that experts have been asking for years: why girls get diagnosed later."

A Swedish cohort of over 2.7 million people born between 1985 and 2020 was followed from birth to a maximum age of 37. More than 78,000 individuals received an ASD diagnosis. Male-to-female diagnosis ratio in early childhood before age 10 was 3:1, lower than earlier 4:1 estimates. Diagnosis rates converge with age and are nearly balanced by age 20. Detection increased throughout childhood, peaking for boys at ages 10–14 and for girls at ages 15–19. Later diagnosis in girls remains unexplained. Registry-based, passive case ascertainment limits full generalizability to populations beyond Sweden.

Read at english.elpais.com