Why do people confuse mental retardation with mentall illness so often?

from some of the answers I've read here it seems to me that some people think someone with down syndrome is the same as someone with schizophrenia. Can someone here explain how they are different?

Becasue they are mentally retarded when it comes to understanding the difference. Pun intended.
People also think if someone who is blind or has cerbreal palsy or anything that doesnt look normal they are mentally retarded.
Ever see someone's tone change to baby talk when they see someone in a wheelchair? Gee they are paralyzed so they most be reatrded.

Down's Syndrome is genetic. Schizophrenia is a mystery. Many different types.

It's a total lack of knowledge of their differences. Ignorance all the way.

Downs is a birth defect that has associated illnesses with it. Sczhisophrenia is a disease in and of it self. they are often confused by the general public through lack of education.

because most people pick up on the word mental and because they are undereducated believe the two conditions to be the same thing

Why confuse them? People lump together everyone they feel superior to. They don't care if people are really different from each other, because those differences aren't important to them. From their point of view, a mentally retarded person doesn't think right, niether does a schizophrenic.

I think its because they lump everything under the term "mental problem." But I would imagine they do know the difference.

I think tht the most of the people having mental disability also face mental illness...like depression e.t.c.I don't know the scientific answer about it but I can imagine tht these people are isolated and not well treated so tht's why they get under mental deseases.Schizoprenia is a hereditary desease and is not caused due to down syndrome.That's all I know.

the medical profession lumps them together so that leads those who are to dumb to treat people like people.the biggest differnce
downs is present at birth (and they can have mental illnesses)
and schizophrenia doesnt show up until in young adulthood.also downs kids have pshysical differnces and schizophrenia look just
like me or joe nobody.merry christmas