My dh is very depressed.
Unfortunately... And very sadly... You cannot help someone who refuses help. I hope you can talk to his Dr and tell him/her in confidence that he is not taking the medication.
You say that you are afraid for your husband - Is there any part of you that is afraid OF him?
Does he threaten to do anything to you or himself? Can you explain how he is on the verge of a breakdown?
there are holistic approaches to treating depression. Im kind of with your DH on this one, there are some pretty funky side effects that go along with medication.
With that said. Do you think he would be open to looking at natural treatments.
Diet wise. There is a link between sugar and depression. The same goes for caffeine. There are studies that show that sugar consumption is linked to the blues.
Exercise is also a great mood booster. Would a gym membership open up an opportunity for him to not only exercise but get some time for himself to unwind? I know with my DH there is a very significant difference in his mood, in direct relationship with working out. A long run does wonders for him.
It maybe time for him to look into individual therapy as well.
Essentially, this is all on him. He needs to be the one to want to feel better and be willing to do what it takes to achieve that. But you could at least suggest these alternatives if you haven't already.
I think that depression clouds the thinking. I doubt his meds will have any worse side effects than what he's headed for without them. I guess you could talk to his doctor. Good luck.