I'm actually not sure that allergies are any more prevelent now than when we were kids, but I do think a lot of moms are a lot more paranoid. Their kid breaks out in a small rash once that might be attributed to eating peanut butter and suddenly their kid is hyper-allergic to peanuts and must never be around them.
As far as ADHD, it was definitely around 40 years ago--but those kids were just labeled troublemakers, put on a vo-tech path, and that was the end of it. Personally I think that ADD is probably the most misdiagnosed and over medicated thing going. I've seen a lot of kids dx as ADD who were simply the products of bad parenting and teachers who had no idea of how to keep kids interested in the course materials. I personally know at least three families who were treating their kids with Ritalin--those kids were normal, active kids who were about as ADD as the family dog--but the minute the teacher mentioned the kid was having trouble concentrating in class just before lunch time (duh--they were hungry!) the parent rushed them off to the doctor, who just like over prescribing antibiotics because that's what the paretns demanded, they prescribed Ritalin for ADD. It's pretty sad.
Anne