Depression Supporters Support Group
This community is dedicated to spouses, children, relatives, co-workers and others who are actively supporting someone suffering from depression or other serious mental illness. Depression can bring about intense sadness, melancholia or despair that has advanced to the point of being disruptive, which can have a grave impact on the ability of others trying to help.

It is good to hear she is on anti-depressants; that shows she acknowledges her medical issue. Yes, I believe the next, most powerful step is for her to seek therapy. A professional should be helping your marriage succeed amidst these difficult realities. Perhaps couples therapy would be good too. I have done both and found individual and couples therapy important.
I know that supporting someone with depression is a slog; and my goal in differentiating between someone-with-depression and someone-against-depression was to show that they have a level of responsibility to fight against their disease, not just let it run the show. From the many posts I have read on this blog, that seems to be an important difference between the many relationships.
If you believe your spouse is not "against-her-depression" then it may be time to bring this up to her, if you have not already. This will need to be a delicate conversation, one maybe best done in therapy.
Good luck.