Elavil and other tricyclics work centrally in the brain to raise serotonin, which then dampens the pain cycle in the brain.

There is a neurological pain loop, that moves throughout structures, including the emotional centers which interpret the signals. Antidepressants moderate and reduce the subjective reaction to the pain.

This pain loop is complex, and I saw it at a seminar. But I cannot find a diagram of it on the net without payment to the various journals.

There are other ways you can try and raise serotonin.
One is light therapy (used in seasonal affective disorder)

Another is use of certain foods. (see the book Food and Mood)

Another is using tryptophan at bedtime and B6, which are needed
for serotonin synthesis. L-tryptophan is now available again, so that 5HTP doesn't need to be used. This is milder than drugs.
This website explains it a bit, (and you don't have to buy the products listed there)
http://www.raysahelian.com/serotonin.html

Using serotonin increasing supplements should not be done with DRUGS like you are taking- as it may be additive and cause serotonin syndrome. If you go off the Elavil, you might want to try this instead.

TCAs like Elavil also have a mixed effect on norepi levels in the brain. Because of this dual action, they tend to be more effective than pure SSRIs.

So Elavil is a complex acting drug.

In general the TCAs do not relieve pain. They alter your perception of the pain.

I myself have chronic arthritis, and seasonal depression when day length gets very short. When I started my light visor last Feb, I noticed a distinct reduction in pain levels, as my sleepiness went away. Everyone is different, but you need to support serotonin synthesis with proper foods, and vitamin B6. http://en.wikipedia.org/wiki/Pyridoxine