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

The study published in The BMJ is based on solid foundations, both in terms of the track record of the teams behind it and the quality of the Swedish registry system. It works with a large and well-documented population cohort, allowing it to analyse the evolution of autism diagnoses with a consistency that is difficult to achieve in other countries. 

Although there are clear limitations—including that its conclusions can only be considered fully generalisable to the Swedish population, that it is based on registered diagnoses (passive cases), which reflects detection patterns rather than true prevalence, and that it does not incorporate comorbidities that could influence the age of diagnosis—the results are consistent with the most recent evidence. Overall, the data suggest that the traditional difference between males and females may be less pronounced than has historically been assumed. As age increases, diagnoses in females increase significantly and the gender gap tends to narrow, pointing to a significant component of initial under-identification. 

In childhood, many girls have more elaborate social skills, exhibit fewer repetitive behaviours, and tend to have better language development, all of which can attenuate or mask the signs of autism. During puberty, however, many of them experience a more marked decline in social functioning, at which point the difficulties become more visible and therefore more likely to be detected. Added to this are social expectations and biases in clinical and educational practice that favour earlier recognition in profiles considered typical of males.

Taken together, these findings invite us to review and adapt our screening and diagnostic practices, and also to adjust interventions to ensure more equitable identification and more timely and effective clinical and educational support for girls and adolescents.