Joshgem; It is wise to tell them you were on anti depressants, regardless of a urine test, they will still be asking you all about your past medication prescriptions and hospitalisations even your family's history at some airlines. Omitting information can be grounds for a fail if found otherwise.
You can't be discriminated against for being on anti-d's. And the reasons therein are not going to affect your job as a FA. Anyhow, I have heard they give you the opportunity to state why you were on that medication or had that operation etc.
Perhaps someone who has done the
VB medical can clarify?