Hello, I Have Been Questioning My Daily Medication For Some

Hello, I have been questioning my daily medication for some time now. Although it helps with my anxiety issues, I am afraid it is the cause of my tremendous weight gain. I have never had a problem with my weight I have always stayed around the same even after my first born I quickly went back to my normal size, but ever since I started my anxiety medication, Ativan, last December i have noticed weight just piling onto me. I am 5 ft 10 inches tall a 27 year old female and before starting this medication I weighed 185, last december, today I weigh at 230 pounds! Is my medication the cause of my weight gain?? Can it cause that much weight gain?