Is it possible that i am gaining weight from remeron or zoloft (sertraline)?

Not the first: Although more commonly seen with remeron, zoloft and any ssri antidepressant can cause weight gain. In general, a 10 to 15lb weight gain is reported by some, but not all, with remeron. Weight gain with zoloft is usually not as dramatic, but there are exceptions of course. Of the two, zoloft is less likely to cause weight gain. Wellbutrin and Effexor (venlafaxine) are least likely to cause weight gain.