I was on Effexor for over 3 years - 150 mg per day with some side effects. Kept my mood stable, but the side effects were no fun at all. I know that they are not addictive, and that almost all anti-depressants work the same way. HOWEVER, when I came off of Effexor, I did it cold turkey - -which docs will warn you not to do. I did iot involuntarily, I was in Latin America and had my bag stolen, no way to get a refill where I was. It was a hidden blessing, as I feel I am better off now without the drug, but the withdrawal was hell, including severe mood depression, sleeplessness, and thoughts of suicide, but I was unable to get a flight out for three days anyway and the worst was over by then. I do not recommend anyone on any anti-depressant to try it this way.
I think it's extremely wise to continue seeing a psychiatric professional while you are on meds, not just a family doctor, as others here have indicated, it seems that often times people only need meds for the harder periods of time in your life or because of significant emotional trauma. Pharmaceutical companies would love for you to take them for a lifetime, but that isn't always necessary.
Thanks to all!
Brett