There are large cross-cultural differences in groups seeking and getting diagnoses, so it could be the case that white middle-class boys are being over-diagnosed while lower-class black girls are almost certainly being hugely under-diagnosed.

In Europe acceptance of ADHD has lagged behind the US but you'd expect stronger institutional health-care systems to reduce cultural differences somewhat.

In many parts of the US, school nurses and teachers are critically involved in identifying kids that might have ADHD and getting them on the track for treatment (whether that treatment is medicinal or purely behavioral intervention). In my experience they don't push it, but they let parents know what resources are available, and have contact info for low-cost or cost-deferred pediatric clinics that can give the actual diagnosis.

Europeans tend to gasp with horror that the school system is "pushing drugs on kids." But it's really more that through the school system the kids and their families have access to free medical advice and social services. So whereas in Europe you might have to remember to ask your general/family practitioner when you see them once a year, in the US there's a team of professionals working through the school system that are making sure kids have everything they need to succeed. Usually that's things like free food so they're not hungry or school bus transportation, but in ~5-10% of the cases it means ADHD diagnosis and treatment. So while this a bit less than double the percentage of kids that get ADHD diagnosis in Europe, it makes a bit more sense in context.