Hi Ladyphin

This is something that you definitely want to tell your doctor so that he or she can recommend something which does not interact with your particular antidepressants. 

You might want to see if there is any underlying medical condition like an underactive thyroid which may be a cause of weight gain.

Also...I just wrote an article in a two part series all about antidepressants and weight gain.  It very well may be that your antidepressant is causing you to gain weight.  You can find Part One of my series here.  A lot of people are chiming in with their experience so do stop by to read.

I hope this helps some and thank you for your question!