I have been helped a lot by taking Prozac. It started out for depression but strangely and wonderfully, it made a huge difference with my TMJ. The pain was practically controlled with only minor flare-ups. Later on when my TMJ flared-up really bad because of big-time stress, it seemed to stop working but whenever I would wean off of it, the pain would be even worse. I then read that SSRI anti-depressants (Prozac is one) can cause night-time clenching. The solution was to change to a different type of anti-d or to add a small dose of Buspar to the Prozac. I opted for that and take 7.5 mg per day with the Prozac. It wasn't too long afterwards that my TMJ did settle down and has been since. I also made many other changes, but I do think this helped.
There are many different classifications of anti-depressants. Some have shown to help relieve pain, but not all. Zoloft and Prozac are both SSRIs but Zoloft did nothing for me. It can be quite difficult to find the "right" one from the "right" classification. I know I can't take Wellbutrin as it makes me irritable and hyper (not good for the jaw).
Do a lot of research before deciding on which kind(s) to try. The type that Cindy mentioned is a Tricyclic, then there are SSRIs, SNRIs, MAOIs, NDRIs, the list goes on. Here is a good website to start your research -
http://www.mayoclinic.com/health/antidepre
ssants/HQ01069
I will say it can be quite difficult to find the perfect anti-d. We are all so different and so alike all at the same time, but if you think they will help - try it (with lots of patience).
God bless...
Carol