Several studies indicated that antidepressants may cause weight gain when taken long term, especially paroxetine and amitriptyline (with average weight
gain of 5 to 6 lbs). However, it is not conclusive if it is depression
the disease itself, specific antidepressants, and/or the combinations.
I strongly recommend for you to consult your healthcare provider about your weight gain and perhaps consider an alternative to paroxetine, if it is the main cause.