Oooooh CQ, you said the "a" word. Technically, withdrawl syndromes are not exclusive to psychotropic medication (a minor detail that the folks at "PROZAC-BUSTERS.ORG", or "PAXILMADEMEIMPOTENTSOMYWIFELEFTMEFORMYBESTFRIENDSDAUGHTER.com fail to mention; and these withdrawl symptoms are really only signals your body is sending that something has upset the balance (homeostasis, or status quo).
In the case of SSRIs; in some people, when you stop these drugs abruptly and the body is not able to fully compensate for the missing serotonin, hence withdrawl symptoms.
In the case of §-blockers; stop taking this drug abruptly and your blood pressure goes through the roof. No one ever has set up a "I HATE INDERAL" site. That's probably because those who experience §-blocker withdraw have bigger problems than those who having problems withdrawing from Paxil. Even many of the 'lucky ones' in the §-blocker-withdrawl group are recovering from heart attacks and strokes.
Now it's time too metaphorize this concept (À - sounds like an "android with glasses" - bptoo, you consider yourself a wordsmith ... what word was I looking for). Let's say that you really, really liked prunes. You began to eat them morning, noon, and night; pounds and pounds per day. When you first start eating prunes, you notice that, when going to the toilet, you often pass softer stools. But, as the months and years scream by, there is a strike by the prune pickers (well, I guess that they would technically be plum pickers). The union, the PP&PU (Prune Pickers & Packers Union), forces a shutdown of the local plant and bans the import foreign prunes. You have to stop the prunes cold turkey. What happens to you? Well, two weeks later you realize that you haven't had a bowel movement. Your body adapts .... to a certain extent - to the various pressures and stresses that we apply to it. The longer and more often we do something, eat something, produce something the easier it gets (ie. practice makes perfect).
A major part of addiction is craving. Junkies end up patterning their life around drug use. A small group of cells in the junkie's brain likes being bathed in dopamine; the nucleus accumbens - and interconnected structures - are involved in sexual gratification, mood, and vigilence.
Many of the drugs of abuse affect the level of dopamine in the nucleus accumbens, artificially raising the levels resulting in being more active, greater mood swings. If you stop giving the drug, dopamine levels in the nucleus accumbens plummet, and withdrawl effects will appear.
Addiction and withdrawl symptoms are often seen together, but these terms are not mutually exclusive. Each concept can be understood on it's own.
- Cam (now stepping down from his soapbox and giving CQ a big hug for jumping all over her about the SSRI/addiction scandal).
<font color=blue>"Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing happened."

- Winston Churchill</font color=blue>