I'm not saying that it's not horribly detrimental. I'm just saying that it has some small benefits. Nicotine can cause weight loss, act as a stimulant, and reduce stress. Though all of those benefits can be gotten a lot safer ways.
Nature ran an article about how a patent was keeping an arsenic based cancer drug out of reach of patients.
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.
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.
Nature ran an article about how a patent was keeping an arsenic based cancer drug out of reach of patients.
Nothing is all bad.
http://www.nature.com/nm/journal/v13/n9/full/nm0907-1005.htm... (subscription required)..