I've had ECT before to come out of a deep depression - one where I was in the hospital and had stopped eating and even biting my nails (a nervous habit of many years). It helped more than any medication did - if it weren't for the memory-related side effects I might have been doing maintenance treatments to this day. It's good for coming out of rock bottom.

I am not sure how it works on blunted emotions but it's worth a shot if nothing else is working. I would definitely make sure that you try natural solutions just in case those work, such as exercise, meditation, etc. The cognitive effects of ECT are not to be taken lightly and should only be used as a last resort.