I had ECT for severe depression that wasn't getting any better with meds or other options. It was a last resort treatment. I got so bad that I was in the hospital, had stopped eating, and even stopped chewing my nails (a big sign, since I always chew my nails).

So nope, it doesn't need to be psychotic depression. Not even sure if they use ECT for psychotic depression, but I have no clue.

ECT worked very well by the way, but it shouldn't be the first line of treatment.