Yes, some medications will cause weight gain, even if you starve yourself. Pdocs will tell you that you will gain weight b/c it increases your appetite (which some do, but that isn't always why you gain) & they will mitigate how much of a weight gain you can expect b/c they know that you probably won't agree to go on it if they tell you the truth. Some people think the benefits of the meds "outweigh" the side effects, but I won't stay on anything that causes me to, & haven't found any med that works well enough for me. I would give it a try to see how much it helps you. You can always stop taking it.