I battled depression for a decade or more prior to dx with early PD, and I mean EARLY. My motor symptoms were extremely mild (left foot dragging slightly, some balance problems, slight tendency to stoop at the end of the day, slight bradykinesia), and they still are. What blew me out of the water was the effect sinemet had on my depression! I was already on two antidepressants (went through several trying to find the right combination) when the neuro prescribed sinemet to check out "possible PD". It was the best antidepressant of any I had previously tried. I really don't think the relief of my mild motor symptoms had that much to do with the dramatic way that the "cloud" lifted.
I took medical leave prior to dx because the depression made it impossible for me to function as a teacher and researcher. It had gotten so bad that my department head asked me to resign my tenured faculty position. Instead, I was able to keep my job by taking several months of leave under the care of two great professionals. It was during that period in 2001 that I began sinemet and confirmed the PD dx. When I returned to work, my department head was delighted with the change in my affect and effectiveness.

Bottom line: nonmotor symptoms nearly did me in. Perhaps if my motor symptoms were more severe I would see it differently. Whether it is DM neuroprotection or a sinemet honeymoon (or a combination of the two), I thank God for it!

Robert