I cant' be sure on this as I am not a doctor. It is very possible that the medications that you are on could be contributing to this.

SNRI's can have a "switch" effect on some people. Other AD's can do this as well. It happened to me. I was put on AD's that pushed me over into a hypomanic state. I had more energy but it was not my norm. SNRI's have become part of the regimen of AD's for ADD. Maybe you are on to something or maybe you were a bit manic and had more productivity on the SNRI. You are either switching into more productive states on certain AD's or you may have a disorder that the doctors need to evaluate.

I hope my experience gave you some clues. Regards.