You will get drunk quicker, and with less alcohol. If it normally takes 4 beers to get you drunk, it will now take about 2. I would suggest that you try drinking a beer a couple days before the party to see how you react with it, since it could cause you to get a panic attack. Other then that, you should be fine...just DON'T DRIVE.
25mg of Zoloft daily is 1/4 the dosage most adults are on, so you shouldn't be affected as much as other on 100mg-->200mg. I wouldn't do any binge drinking since excessive alcohol and Zoloft can cause serious breathing difficulties.