You're not completely incorrect, again it's each diagnostician.
In the uk nhs (socialist healthcare system )gps gave out antibiotics like sweets, now you are barely ever prescribed them, then again! if you are celine dion singer, your gp(md) might prescribe you anything! manufactured at any dose, it's down to the individual, in the 1960s everybody was kanners or aspergers which in the uk was very rarely diagnosed in the 60s, jump ahead to the 2000s very common place to be diagnosed,which is very strange(lower percentage of diagnoses in the 60s) with the reputation for english eccentricity(really autism)