Very anecdotal, but I know multiple people who are addicted. Could very well be psychological, but if they go more than a day or two without smoking they are terrible to be around. Which sucks because I'm stuck with
A) don't be around them
B) be around them while they are baked and smell
C) be around them while they are terrible
I've been sticking with A for the time being, but it sucks because I feel like I've already lost a few friends when I stopped smoking and it seems like that is their whole life.