After smoking from my 13th 'til my 27-28th, I quit smoking with the help of Champix.
When I asked my doctor what exactly the stuff was, he explained that it was originally developed as an anti-depressant; but the product failed and now is used to help people quit smoking.
The instructions leaflet (is that how it's called in English) mentioned at least 10 times that you and people surrounding you should watch out for signs of depression and feeling suicidal; along with some other fun side effects.
So yeah..... It started very encouraging.
I took 'em regardless, for 3 months.
You start with a starter package for 3 or 4 weeks, slowly increasing the dosage. After that you go to the doctor again to see if the stuff it's doing to your brain and mood isn't too bad. If the signs aren't too bad, you get the rest of the pills.
The 3 months I took the pills, I walked around like a zombie. I had to explain to my boss that I was taking these pills an what they did because he was concerned about the drop in my job performance. Things happened and I'd just, you know, watch and think or feel nothing about it. People that knew me frequently asked if I was okay, if I wasn't feeling well, that I seemed really distant.
Only good thing was, it was the same with quitting smoking. I just didn't give a damn about cigarettes anymore. I tried smoking once or twice during the course -somewhere at the end of the first month- and recognized it to taste like crap (well, ashes and other burnt stuff) and tossed the cigarette away after one or two pulls.
Two years later now and I'm still not smoking. I still get a slight urge every once in a while (usually on 'occasions' with plenty of food and drinks), but it's happening less and less frequently and I never had a problem just thining "nah, best I don't smoke".
But truth be told, to me the major incentive not to take up smoking again is because I never, EVER, want to have to take those damned Champix pills anymore. The stuff it does with your head... like you're a bystander to your own life, like nothing means anything... I'd never recommend it to anyone. But it does get you off smoking, I guess...
Still, don't take 'em unless you're sure your mind and emotional state is up to it and you can surround yourself with people who can help you through it. The stuff is poison and while I'm glad I stopped smoking, looking back, I'd never do it again with those drugs. Had I know then what I know now, the mere thought of them would've been enough to just quit smoking.