I'm an MDD lifer, too. Even with meds I still needed to undergo ECT to get me out of the deepest, darkest depressive episode I have ever experienced. When I was hospitalized I was moments away from ending it.

ECT did work, but it doesn't cure depression. It's used to treat episodes to a point you can control your depression by other means. You can under go maintenance treatments as well.

I did experience memory loss beginning just before I was hospitalized and lasting for a few months after I was done. But my some of my memory did come back as people filled in the blanks.

Actually undergoing ECT is not a big deal. You are under anesthesia for a very short period of time, while they are performing the ECT. I was groggy after for several hours and I was nauseous as well, but that's how I've always reacted to anesthesia.

It's worth discussing with your T.