Most likely, yes, assuming along with keeping the same eating habits you also kept the same exercise habits. If you decreased exercise, then that might have been the problem. Frankly 10 pounds isn't really much for serotonin affecting drugs. It can be a whole lot worse. But over a long period of time you probably would have kept gaining. For me, my weight gainer was Paxil, which is more likely to be a big weight gainer than Effexor because Effexor is a stimulating drug that affects norepinephrine as well as serotonin, while Paxil only affects serotonin, but I gained 50 pounds over a period of years. When I stopped I almost immediately lost 30 of those 50 pounds, but not the other 20.