Clinical depression is a serious, debilitating, and often fatal disease, but you know exactly what I mean when I say I'm depressed because my hard drive died.

Clinical depression is a serious, debilitating, and often fatal disease, but you know exactly what I mean when I say I'm depressed because my hard drive died. These shifts happen all the time; linguists call them euphemistic (or dysphemistic) treadmills. There's a nonprofit advocacy group for the rights of the mentally handicapped called "Friends of the Retarded". At the time it was founded, that was the most euphemistic and inoffensive name that came to mind. "Slow" was too insulting, so they had to replace it with a Latin-derived synonym. Now anyone that makes a bad move while playing blindfolded chess is instantly a retard. Similarly, "idiot", "moron", and "imbecile" were once scientific terms to describe different severities of retardation. "Autistic" is especially justified, because the connotation of "geek" has shifted from a definite negative to a mild positive. People like to be thought of as geeky, and so now everyone is, which weakens the term. If you refer to your vacuum-cleaner-collecting friend as "really geeky" people will just think he reads Slashdot or something.