I had an antidepressant stop working on me -- it was Nardil which is an MAOI. I believe they're the oldest class of antidepressants and are rarely used any more because there are many food restrictions and med restrictions while a person is on an MAOI. If you eat "forbidden foods" or take meds that are not safe with an MAOI you can have a dangerous rise in blood pressure which can be life threatening. That being said while the Nardil worked I felt like a new person and was really happy for the first time in my life. For some people MAOI's are the only antidepressants that work. Just something to keep in mind if all else fails. Also there is one tricyclic antidepressant that works on depression as well as obsessive compulsive disorder -- it's called Anafranil. I know what panic type anxiety feels like. Quite a few years ago I was taking an antipsychotic for severe anxiety and to help with sleep (along with an antidepressant and other anxiety meds) and the antipsychotic (Risperdal) quit working out of the blue. It had worked for years. My friend said to me you're doing worse right now than when your husband died. I was really scared because I'd been stable for so long. I went on a different antipsychotic and thankfully that stopped the anxiety. Some of us need to take more than just one medicine and having a therapist can also help.