I assume you're being sarcastic, but moron, retard, stupid, dumb, idiot, mad, imbecile, mongoloid, spastic, lame, lunatic, maniac and psycho were all used as me

I assume you're being sarcastic, but moron, retard, stupid, dumb, idiot, mad, imbecile, mongoloid, spastic, lame, lunatic, maniac and psycho were all used as medical terms before they became stigmatic. Filter out sexual and scatological insults and there is very little left.