Hi there, thanks for asking. It is possible that the dose of cymbalta is not enough so you experience the anxiety in the hours that blood level of the medication is low. It can easily increased (and gradually) to 120 mg a day. If cymbalta causes the anxiety, it usually manifests the problem first with sleep problem. If you do not have it, we can be sure about the fact that cymbalta is not causing the anxiety. On the other hand the anxiety caused by this medication usually appears in the first few weeks, not in the long term use. I wish you a good health.