ai_ayumi
I have been on and off of anti'ds since the early 70's. There is not an easy answer to your question, though.
Prozac didn't work for me, but it does for others. I remember when it came out it was considered a wonder drug because one of the side-effects that some people experienced was losing weight. It didn't help me there, either.
There are so many anti'ds available that the one that works best is the one that works best for you. You will only find out which one and what dosage by taking different ones and different dosages.
Basically there are two types of antidepressants which work to increase or decrease the neurotransmitters of the brain, serotonin and norepinephrine. Some meds affect serotonin and some affect norepinephrine and some are a combination of the two.
Here is a site with some more specific info
http://www.healthyplace.com/Communities ... /index.asp
The anti-d that has helped me most recently was Cymbalta. It seemed to work really well for about a year, but now I am not seeing as good of results. I am also on Celexa and Xanax for PTSD.
The most important thing is to continue to monitor how the anti-ds are affecting you either for the good or bad. If you find that they are not working or working as well, go back to the doctor and see what adjustments or substitutions can be made.
Good luck...
N.