Cymbalta (also called Cimbalta in some countries) is the brand name of an antipsychotic drug called duloexetine. It is indicated in Major Depression. Its side effects include dizziness, vertigo and gastro-intestinal upset. In all likelihood you suffered from the known adverse effects. It can only be definitively proved if the same side effects are experienced on re-challenge (i.e. when Cymbalta is taken again).