[scott_s]

As you pointed out, nicotine is a stimulant; I doubt it's the nicotine that reduces stress. What's probably happening is that when a smoker lights up, their brain releases dopamine because they're finally getting what they're addicted to.

In the same manner, a cup of coffee can relax someone if they're a caffeine addict.

[colins_pride]

One of the things I've struggled with is figuring out if I'm addicted to something ..

One way to judge is to look for withdrawal symptoms, but this requires changing my behavior to test ..

So the idea is that if something that stimulates most people, and used to stimulate me, now relaxes me, I've become dependent on it ..

Very intuitive

[chris11]

That is a good point. When addicts use drugs their stress is reduced. But nicotine is unique in that its profile depends on the dose.

When smokers want to have more concentration, they take short and quick puffs. This gets a low level of nicotine in the blood. At a low dose, nicotine increases norepinephrine and dopamine. So it acts like a stimulant.

When smokers want to relax, they take long and deep puffs. This increases the dose of nicotine. And at high doses, it affects serotonin and opiate levels in the brain and acts like a sedative.

http://en.wikipedia.org/wiki/Nicotine#Psychoactive_effects

[kingkongrevenge]

I guess you could form a complicated theory like that. Or you could try smoking a cigarette and notice that it relaxes and focuses you.