That dovetails with widespread anecdotal tales of mood modulation, if you’re tired it helps keep you alert, upset it helps calm you down, etc.
Exactly. A nicotine patch, BTW, is a great, but controversial, treatment for ADD. Certainly tweaks the dopamine system.
Also, recall the “kindness” of giving the condemned man a last cigarette before the firing squad, and such.
As with many substances - and many other things that can affect us as well - tobacco can be medicine or poison, depending on dose and such.