Elavil is amitriptyline, an anti-depressant. If the weight gain bothers you, you might ask if it could be changed to trazodone which doesn't make you gain weight and is an effective anti-depressant also.
Yep! I've been on Lexapro for several years and I gained a lot of weight, particularly soon after I began the drug.
Elavil inhibits histamine action in the central nervous system and long term inhibition of histamine receptors in the brain causes deranged metabolism, which can lead to weight gain.