Yes, the medication could be a cause, though it also might not be the cause. Antidepressants can be hard on magnesium absorption, which is essential for relaxing muscles and proper digestion. But as I say, it could be something else, too. One thing also common to medications are stomach problems. If you just started the med, and nothing else you can think of happened and this has never happened before, well, it's often been suggested to me that one thing following the newest thing you've done differently is rarely a coincidence.