Tracking nicotine vs your mood strikes me as being "research" -- especially since there wasn't a previously-known scientific correlation, as demonstrated by the recently-published results! Instead... I'd be glad that there is finally some evidence to explain your observations, and be hopeful that it results in new treatments.
(Also: Pawning off laziness onto others is a cop out. You could've pushed the research forward by doing more than just telling your doctor. But you didn't, I presume. Why is that...?)