Steph, since he's doing a study, it's probably true that he can't take antidepressants. It would compromise his response to the side effects of the study treatment.
Has he ever talked about his hep C diagnosis at meetings and the fact that he is on treatment, which is very difficult? It can absolutely be hell for some people.
Also, suggest he do a Gratitude List. That always brings out the positive. When people are on a pity pot, it's the last thing they want to do, but it's a mood changer. And don't forget the basics--Steps 1 through 3. He just needs to substitute "powerless over side effects" for "powerless over alcohol." I call it the "1-2-3 dance" and have done it often. It took me through hep C diagnosis (which I shared at meetings) through liver cancer and beyond--to what does the future hold?
But yes, also remember to take care of yourself.
Hugs,
Connie