Western psychological discourse does of course evolve over time. New words, or new uses of old words, enter the language. These are perfectly normal developments of our language. It is hard to me to imagine that people could become comfortable using the language of neuropsychology when talking with each other about how they feel. It turns out, though, that the Decade of the Brain and the massive rise of psychopharmacology are already having their effect on the way people talk about themselves.
People increasingly describe emotional disorders as chemical imbalances in their brains.
I notice this with some students. Another dramatic example came at the last AAPP conference, when one of the speakers reported that patients sometimes tell him that they feel that their neurotransmitters are out of balance. The National Alliance for the Mentally Ill is insistent on the idea that all mental illness is a disorder of the brain. Of course, this statement, as a universal claim, doesn't stand careful scrutiny. It is motivated far more by the need to take the pressure and stigma of mental illness away rather than medical science or ethical reflection.