D'après mon expérience avec les parents d'enfants avec Trouble du spectre autistique, l'alimentation est à l'origine de cette hausse et exposition aux écrans avec connexion internet (champs magnétiques et ...
The increase in the number of people diagnosed with ASD is primarily due to two reasons: 1) recognition of the spectrum form of autism, and therefore a broad profiling of autistic people (this results from the change from ICD-10 to ICD-11) 2) higher competences of diagnosticians, better tools and easier access to diagnosis, especially for women.There are others, but those listed above are the most important.
Katarzyna Grzesiak-Bramańska has already listed the most important reasons - I'd only add that growing social awareness of the ASD (and neurodiversity in general) also plays a major role here, that is more people (especially adults) are looking for a diagnosis, based on the knowledge they've obtained through media and social media
I confirm what Mr. Jan Gierzyński wrote. Currently, the generations previously undiagnosed are coming to the fore - I am also a woman with a late diagnosis of ASD (I was diagnosed after my children). They gather on internet forums and in self-help groups because they feel the need to take care of themselves, to find an explanation for the sense of social disharmony, and having lived for many years without proper, professional support, they often paid a high price - health problems or multi-level social exclusion.
Adding to the excellent previous posts from Katarzyna Grzesiak-Bramańska & Jan Gierzyński: there is also evidence that the increase of autism diagnosis is correlated with decreases in diagnosed rates of other developmental disabilities such as ID; which suggests that the “increased” diagnosis of autism is more akin to a regression to the mean. As the changes in diagnosis criteria and how those criteria are displayed in previously disenfranchised groups. I believe that we will reach a peak and rates will somewhat “normalize”.
We may also, again, see a fracture of diagnosis as some scholars push for a distinction for “profound” autism or if others identify phenotypes or we simply alter the way we conceptualize the “disorder”.
As an autistic person, but also a clinical diagnostician for the autism spectrum, I do not believe that ASD is overdiagnosed (although it happens that the wrong people receive the diagnosis). I see and sense people on the spectrum who do not have a formal diagnosis. They are most common in the 40+ generation, especially seniors (I call them the lost autistic generation).
I agree with the Andrew M. Colombo-Dougovito's thesis that in time we will reach a diagnostic peak, after which the number of ASD diagnoses will normalize.
I would like to draw attention to another problem that may generate overdiagnosis and misdiagnoses. Namely, the symptoms of ADHD and ASD with normal intelligence may be so similar that without a multi-tool and multi-aspect diagnosis, the diagnostician may make a mistake. What is more, in Poland, specialists have an additional dilemma - the state support system rewards autism. Children with a formal diagnosis of ASD receive a high (for Polish conditions) subsidy for therapy, while children with a formal diagnosis of ADHD receive nothing, although it happens that their functioning is worse than autistics at some stages of education. I wrote more about this on my FB blog, link here: